The answer is to add the kms:Decrypt permission to the SageMaker execution role. This is required because when data is stored in Amazon S3 with server-side encryption using AWS KMS (SSE-KMS), SageMaker must decrypt the objects before reading them during training. Even though the role already has s3:GetObject permissions, the KMS layer enforces a separate authorization check, and without kms:Decrypt, the service receives an Access Denied error. On the AWS Certified Machine Learning Specialty MLS-C01 exam, this scenario tests your understanding of how SageMaker interacts with encrypted data sources, a common pitfall where candidates assume S3 permissions alone are sufficient. A frequent trap is confusing read and write operations—kms:Encrypt is only needed when SageMaker writes encrypted output, not when reading input data. Memory tip: “Read to decrypt, write to encrypt”—if SageMaker is reading SSE-KMS data, you only need the Decrypt action.
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.
A data scientist is using Amazon SageMaker to train a TensorFlow model on a dataset that includes sensitive personal information (PII). The data is stored in Amazon S3 with server-side encryption using AWS KMS (SSE-KMS). The training job fails with an Access Denied error when trying to read from S3. The data scientist has already verified that the SageMaker execution role has s3:GetObject permissions on the S3 bucket. What additional configuration is needed?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Add kms:Decrypt permission to the SageMaker execution role.
Option A is correct because SageMaker needs kms:Decrypt permission to read SSE-KMS encrypted objects. Option B is wrong because SageMaker does not need kms:Encrypt for reading. Option C is wrong because S3 bucket policy is not needed if role has permissions. Option D is wrong because VPC endpoint policy is not the issue.
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.
✓
Add kms:Decrypt permission to the SageMaker execution role.
Why this is correct
SSE-KMS requires decrypt permission to read objects.
Related concept
Read the scenario before looking for a memorised answer.
✗
Add kms:Encrypt permission to the SageMaker execution role.
Why it's wrong here
Encrypt is for writing, not reading.
✗
Add a bucket policy that grants s3:GetObject to the SageMaker role.
Why it's wrong here
Role already has permission; bucket policy is not needed.
✗
Configure a VPC endpoint for S3 and attach a policy.
Why it's wrong here
VPC endpoint policy might restrict access, but the issue is KMS permissions.
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: Add kms:Decrypt permission to the SageMaker execution role. — Option A is correct because SageMaker needs kms:Decrypt permission to read SSE-KMS encrypted objects. Option B is wrong because SageMaker does not need kms:Encrypt for reading. Option C is wrong because S3 bucket policy is not needed if role has permissions. Option D is wrong because VPC endpoint policy is not the issue.
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.
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. A data scientist is using Amazon SageMaker to train a model. The training data is stored in an S3 bucket encrypted with AWS KMS. Which TWO actions are necessary to allow SageMaker to access the data?
easy
✓ A.Ensure the SageMaker execution role has s3:GetObject permission.
B.Enable S3 Transfer Acceleration.
C.Set up a VPC endpoint for S3.
D.Add a bucket policy allowing SageMaker access.
✓ E.Grant the SageMaker execution role kms:Decrypt permission.
Why A: Option A is correct because SageMaker needs permission to decrypt. Option C is correct because the execution role needs permission. Option B is wrong because bucket policy is separate. Option D is wrong because it's not required. Option E is wrong because VPC endpoint is not required.
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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.
Question Discussion
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