Quick Answer
The answer is the BlockPublicAcls setting, which applies to both new and existing ACLs. This is the correct choice because it directly prevents any public access granted through object or bucket ACLs, effectively blocking the most common misconfiguration that exposes S3 data. On the AWS Certified Data Engineer Associate DEA-C01 exam, this question tests your ability to distinguish between the four block public access settings, with a common trap being to select the option that only blocks new ACLs, which would leave existing public ACLs untouched. The exam emphasizes that while AWS recommends enabling all four settings for comprehensive protection, the specific scenario of ensuring a bucket is not publicly accessible requires the setting that retroactively blocks existing ACLs. A useful memory tip is to think of BlockPublicAcls as the “retroactive ACL blocker” that catches both past and future public ACLs, unlike its counterpart that only applies to new ones.
This DEA-C01 practice question tests your understanding of data security and governance. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 engineer needs to ensure that an S3 bucket is not publicly accessible. Which S3 block public access setting should be applied to achieve this?
BlockPublicAcls (both new and existing)
Blocks all public ACLs.
IgnorePublicAcls
Why wrong: Ignores public ACLs but does not block them.
BlockPublicAcls (new ACLs)
Why wrong: Only blocks new ACLs, not existing ones.
BlockPublicPolicy
Why wrong: Blocks public bucket policies.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
BlockPublicAcls (both new and existing)
Option B is correct because BlockPublicAcls prevents public ACLs on the bucket. Option A is wrong because it only applies to new ACLs. Option C is wrong because it blocks public bucket policies. Option D is wrong because it blocks public cross-account access. The combination of all four is recommended, but the question asks for a single setting.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
BlockPublicAcls (both new and existing)
Why this is correct
Blocks all public ACLs.
Related concept
Static NAT maps one inside address to one outside address.
IgnorePublicAcls
Why it's wrong here
Ignores public ACLs but does not block them.
BlockPublicAcls (new ACLs)
Why it's wrong here
Only blocks new ACLs, not existing ones.
BlockPublicPolicy
Why it's wrong here
Blocks public bucket policies.
Common exam traps
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
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
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DEA-C01 NAT questions on configuration and troubleshooting.
Data Security and Governance — study guide chapter
Learn the concepts, then practise the questions
Data Security and Governance practice questions
Targeted practice on this topic area only
All DEA-C01 questions
1,786 questions across all exam domains
AWS Certified Data Engineer Associate DEA-C01 study guide
Full concept coverage aligned to exam objectives
DEA-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise DEA-C01 questions linked to Data Ingestion and Transformation.
Practise DEA-C01 questions linked to Data Operations and Support.
Practise DEA-C01 questions linked to Data Security and Governance.
Practise DEA-C01 questions linked to Data Store Management.
Practise DEA-C01 questions linked to DEA-C01 fundamentals.
Practise DEA-C01 questions linked to DEA-C01 scenario.
Practise DEA-C01 questions linked to DEA-C01 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Data Security and Governance — This question tests Data Security and Governance — Static NAT maps one inside address to one outside address..
The correct answer is: BlockPublicAcls (both new and existing) — Option B is correct because BlockPublicAcls prevents public ACLs on the bucket. Option A is wrong because it only applies to new ACLs. Option C is wrong because it blocks public bucket policies. Option D is wrong because it blocks public cross-account access. The combination of all four is recommended, but the question asks for a single setting.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DEA-C01 NAT questions on configuration and troubleshooting.
Static NAT maps one inside address to one outside address.
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 →
Keep practising
Last reviewed: Jun 20, 2026
This DEA-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 DEA-C01 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.