MLS-C01 Data Engineering Practice Question
Which TWO options are best practices for managing access to data stored in Amazon S3 for a data lake?
⚠ Common exam trap
Test-takers frequently confuse encryption mechanisms (like SSE-S3) with access control, or mistakenly think that legacy ACLs are still a best practice for granular permissions in modern data lake architectures.
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
✓
Use IAM policies to control user and role permissions
C is correct because IAM policies are the primary mechanism for controlling access to AWS services, including S3, for users and roles within an AWS account. They allow you to define fine-grained permissions based on identity, which is a best practice for managing access to a data lake. This aligns with the principle of least privilege and centralized access control.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use S3 access control lists (ACLs) for granular permissions
Why it's wrong here
ACLs are outdated; AWS recommends IAM and bucket policies.
- ✗
Enable default encryption with SSE-S3
Why it's wrong here
Encryption protects data at rest, not access control.
- ✓
Use IAM policies to control user and role permissions
Why this is correct
IAM policies are central to access management.
- ✓
Use S3 bucket policies to grant cross-account access
Why this is correct
Bucket policies allow resource-based access control.
- ✗
Generate pre-signed URLs for all data access
Why it's wrong here
Pre-signed URLs are for specific temporary access, not a general access control mechanism.
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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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.