The answer is the notebook instance role lacks the iam:PassRole permission to pass the SageMaker execution role. When a SageMaker training job is launched from a notebook, the notebook’s IAM role must have explicit permission to pass a separate execution role to the SageMaker service via iam:PassRole; without this, the training job cannot assume the role needed to access S3, even if the notebook role itself has s3:GetObject and s3:PutObject permissions. On the AWS Certified Machine Learning Specialty MLS-C01 exam, this scenario tests your understanding of AWS IAM role chaining—a common trap is assuming S3 or SageMaker actions alone are sufficient, when the real bottleneck is the missing PassRole. Remember the mnemonic: “Pass first, train later”—the notebook must pass the execution role before SageMaker can use it.
MLS-C01 Practice Question: Machine Learning Implementation and Operations
This MLS-C01 practice question tests your understanding of machine learning implementation and operations. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An IAM policy is attached to a SageMaker notebook instance. The data scientist wants to use the notebook to train a model using data from S3 bucket 'my-bucket'. However, the training job fails with an access denied error. What is the MOST likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The notebook instance role does not have iam:PassRole permission to pass the SageMaker execution role
Option B is correct because the notebook instance role needs permission to pass the execution role to SageMaker (iam:PassRole). The policy allows s3 and sagemaker actions but not PassRole. Option A is incorrect because GetObject and PutObject are allowed. Option C is incorrect because SageMaker actions are allowed. Option D is incorrect because the resource is correct.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
The notebook instance role does not have iam:PassRole permission to pass the SageMaker execution role
Why this is correct
SageMaker needs the notebook role to pass an execution role to training jobs.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The sagemaker:CreateTrainingJob permission is not allowed on the specific resource
Why it's wrong here
The policy allows sagemaker:* on all resources.
✗
The S3 bucket resource ARN is incorrectly formatted
Why it's wrong here
The ARN is correctly formatted for objects in the bucket.
✗
The s3:GetObject permission is missing for the bucket
Why it's wrong here
The policy includes s3:GetObject for the bucket.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Identify which MLS-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Machine Learning Implementation and Operations — This question tests Machine Learning Implementation and Operations — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The notebook instance role does not have iam:PassRole permission to pass the SageMaker execution role — Option B is correct because the notebook instance role needs permission to pass the execution role to SageMaker (iam:PassRole). The policy allows s3 and sagemaker actions but not PassRole. Option A is incorrect because GetObject and PutObject are allowed. Option C is incorrect because SageMaker actions are allowed. Option D is incorrect because the resource is correct.
What should I do if I get this MLS-C01 question wrong?
Identify which MLS-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. An IAM policy attached to a SageMaker notebook role is shown in the exhibit. A data scientist is trying to run a training job from the notebook, but the job fails with an access denied error. The training job needs to read data from 'my-bucket' and write output to 'my-bucket'. What is the most likely cause of the failure?
medium
A.The policy does not allow s3:ListBucket
✓ B.The training job execution role does not have the same permissions
C.The policy does not allow sagemaker:CreateTrainingJob
D.The S3 bucket is not specified in the Resource
E.The policy does not allow s3:GetObject
Why B: Option C is correct because the policy allows s3:PutObject on 'my-bucket/*', but the training job may need to write to a different bucket or path. Option A is wrong because the actions are allowed. Option B is wrong because s3:PutObject is allowed. Option D is wrong because the bucket is specified. Option E is wrong because the training job role is separate from the notebook role.
Variation 2. A data scientist has this IAM policy attached to their IAM role. They are trying to run a SageMaker training job that reads data from 'my-bucket' and writes output to 'my-bucket'. The job fails. What is the most likely reason?
medium
A.The sagemaker:CreateTrainingJob action is not allowed on specific resources
B.Missing s3:ListBucket permission on the bucket
✓ C.Missing iam:PassRole permission
D.The training job requires permissions to write to CloudWatch Logs
Why C: Option B is correct: the policy does not grant permission to pass the execution role to SageMaker (iam:PassRole). Option A is incorrect because s3:GetObject and s3:PutObject are present. Option C is incorrect because the actions are allowed. Option D is irrelevant.
Variation 3. An IAM policy attached to a SageMaker execution role is shown in the exhibit. When a data scientist tries to create a training job that writes logs to CloudWatch Logs, the job fails. What is the MOST likely reason?
medium
A.The policy does not specify the SageMaker API version
B.The S3 bucket policy denies access to the training job
✓ C.The policy lacks permissions for CloudWatch Logs actions
D.The policy has an implicit deny for SageMaker actions
Why C: Option B is correct because the policy does not include CloudWatch Logs permissions. Option A is incorrect because the actions are allowed for all resources. Option C is incorrect because the S3 actions are allowed. Option D is incorrect because there is no deny statement.
Variation 4. Refer to the exhibit. An IAM policy is attached to an IAM role used by a SageMaker training job. The training job fails with an access denied error when trying to write model artifacts to an S3 bucket. What is the most likely cause?
medium
✓ A.The IAM role does not have permission to write to the S3 bucket
B.The training job is trying to write to a different S3 bucket
C.The IAM role does not have permission to read the training data
D.The IAM role does not have permission to create training jobs
Why A: Option D is correct because the policy only allows s3:GetObject, not s3:PutObject, so the training job cannot write artifacts. Option A is wrong because the policy allows sagemaker:CreateTrainingJob. Option B is wrong because the policy allows s3:GetObject for the training data. Option C is wrong because the policy does not restrict the S3 bucket; it allows GetObject on a specific path.
Last reviewed: Jun 20, 2026
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This MLS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the MLS-C01 exam.
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