MLS-C01 Practice Question: Machine Learning Implementation and Operations
A data scientist is using SageMaker to train a model. The training job needs to access data in an S3 bucket in a different AWS account. The data scientist has set up proper S3 bucket policies and IAM roles. Which THREE steps are necessary to allow SageMaker to access the cross-account S3 bucket? (Select THREE.)
⚠ Common exam trap
Many exam-takers confuse VPC endpoints or KMS encryption as mandatory for cross-account access, when in fact the core requirement is proper IAM role chaining and bucket policy configuration.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure the S3 bucket policy to grant access to the SageMaker execution role ARN from the training account
The S3 bucket policy in the data account must explicitly grant the SageMaker execution role ARN from the training account the necessary permissions (e.g., s3:GetObject, s3:ListBucket). This is the foundational step for cross-account access, as S3 bucket policies are resource-based policies that can specify principals from other AWS accounts.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Configure the S3 bucket policy to grant access to the SageMaker execution role ARN from the training account
Why this is correct
Bucket policy must allow cross-account access.
- ✗
Create a VPC endpoint for S3 in the training account
Why it's wrong here
VPC endpoints are for private connectivity, not cross-account access.
- ✓
Create an IAM role in the data account with permissions to read from the S3 bucket
Why this is correct
The role in the data account grants S3 access.
- ✗
Use an AWS KMS key to encrypt the data in transit
Why it's wrong here
KMS is for encryption at rest, not required for cross-account access.
- ✓
Configure the SageMaker execution role in the training account to assume the IAM role in the data account
Why this is correct
The training role must have sts:AssumeRole permission.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.