This DVA-C02 practice question tests your understanding of security. 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.
An application uses IAM roles to grant EC2 instances access to S3. The developer notices that the application works correctly in one account but fails with access denied in another account. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The S3 bucket policy does not grant access to the IAM role
The most likely cause is that the S3 bucket policy in the second account does not explicitly grant the IAM role from the first account (or the second account's own IAM role) the necessary permissions. When an IAM role is used, both the role's trust policy and the resource-based policy (S3 bucket policy) must allow the action; if the bucket policy denies or omits the role's ARN, access will be denied even if the role itself has S3 permissions.
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.
✗
The IAM role is not attached to the EC2 instance
Why it's wrong here
If the role were missing, the application would not get credentials at all.
✗
The EC2 instance does not have internet access
Why it's wrong here
Access denied suggests a permission issue, not network connectivity.
✓
The S3 bucket policy does not grant access to the IAM role
Why this is correct
Cross-account access requires the S3 bucket policy to explicitly allow the IAM role.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The KMS key policy does not allow decryption
Why it's wrong here
This would only apply if S3 server-side encryption with KMS is used.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume IAM role permissions alone are sufficient, forgetting that resource-based policies (like S3 bucket policies) can override or deny access even when the identity-based policy allows it.
Detailed technical explanation
How to think about this question
Under the hood, IAM authorization for S3 requires evaluation of both the identity-based policy (attached to the IAM role) and the resource-based policy (S3 bucket policy). If the bucket policy explicitly denies access or does not include a matching Allow for the role's ARN, the request fails with an AccessDenied error—even if the role has s3:GetObject permissions. This is a common cross-account scenario where the bucket owner must grant the external IAM role access via a bucket policy statement with the role's ARN as the Principal.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Security — This question tests Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The S3 bucket policy does not grant access to the IAM role — The most likely cause is that the S3 bucket policy in the second account does not explicitly grant the IAM role from the first account (or the second account's own IAM role) the necessary permissions. When an IAM role is used, both the role's trust policy and the resource-based policy (S3 bucket policy) must allow the action; if the bucket policy denies or omits the role's ARN, access will be denied even if the role itself has S3 permissions.
What should I do if I get this DVA-C02 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
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.
This DVA-C02 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 DVA-C02 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.