CGRC Control Implementation Practice Question
You are managing an AWS S3 bucket that stores sensitive PII. Which control is the primary mechanism to prevent public access?
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
✓
S3 Block Public Access
S3 Block Public Access settings provide a centralized, account-wide or bucket-level override to prevent accidental exposure.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Encryption at Rest
Why it's wrong here
Encryption protects data content, not access authorization.
- ✗
Bucket ACLs
Why it's wrong here
ACLs are legacy and prone to configuration errors.
- ✓
S3 Block Public Access
Why this is correct
This is the definitive control to prevent public access regardless of object settings.
- ✗
IAM User Permissions
Why it's wrong here
IAM controls access but doesn't override public settings in the way Block Public Access does.
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 |
About these practice questions
One of 199 original CGRC practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official (ISC)² exam blueprint
This CGRC practice question is part of Courseiva's free (ISC)² 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 CGRC exam.