The answer is that the IAM role is not attached to the EC2 instance. Even if a valid IAM policy grants s3:PutObject permissions, the EC2 instance cannot use those permissions unless the role is explicitly attached to the instance profile and associated with the EC2 resource at launch or via the console. Without this attachment, the instance has no identity to present to AWS, so any S3 upload attempt fails with an access denied error. On the AWS Certified SysOps Administrator Associate SOA-C02 exam, this scenario tests your understanding that IAM roles must be attached to EC2 instances to grant temporary credentials, and a common trap is assuming a policy alone is sufficient. Remember: a policy without a role attachment is like a key without a lock—it grants access but has no mechanism to use it.
SOA-C02 Reliability and Business Continuity Practice Question
This SOA-C02 practice question tests your understanding of reliability and business continuity. 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.
Refer to the exhibit. A SysOps administrator creates an IAM policy to allow an EC2 instance to upload objects to an S3 bucket. However, the instance is unable to upload objects. What is the MOST likely reason?
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 IAM role is not attached to the EC2 instance.
Option A is correct because the policy allows s3:PutObject only, but the EC2 instance likely needs to assume the role via sts:AssumeRole. However, the policy does not include that action. More commonly, the issue is that the policy is missing s3:PutObjectAcl or the bucket policy denies access. But among the options, the most likely is that the policy does not include s3:ListBucket, which is often required for PUT operations? Actually, s3:PutObject does not require ListBucket. However, the typical issue is that the IAM role is not attached to the instance. Option B is correct: The role is not attached to the EC2 instance. Option A is wrong because s3:PutObject is allowed. Option C is wrong because there is no bucket policy shown. Option D is wrong because S3 server-side encryption does not block uploads.
Key principle: ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
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 S3 bucket has server-side encryption enabled.
Why it's wrong here
Encryption does not prevent uploads.
✗
The policy does not include s3:GetObject permission.
Why it's wrong here
GetObject is not needed for uploads.
✗
The bucket policy denies all access.
Why it's wrong here
No bucket policy is shown; it may not exist.
✓
The IAM role is not attached to the EC2 instance.
Why this is correct
Without the role, the instance cannot assume permissions.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Standard ACLs match source addresses.
Common exam traps
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Trap categories for this question
Command / output trap
No bucket policy is shown; it may not exist.
Detailed technical explanation
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
Standard ACLs match source addresses.
Extended ACLs can match source, destination, protocol and ports.
The first matching ACL entry is used.
There is usually an implicit deny at the end.
TExam Day Tips
→Check inbound versus outbound direction.
→Read the ACL from top to bottom.
→Look for a broader permit or deny above the intended line.
Key takeaway
ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
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.
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related SOA-C02 ACL questions on filtering logic and placement.
Reliability and Business Continuity — This question tests Reliability and Business Continuity — Standard ACLs match source addresses..
What is the correct answer to this question?
The correct answer is: The IAM role is not attached to the EC2 instance. — Option A is correct because the policy allows s3:PutObject only, but the EC2 instance likely needs to assume the role via sts:AssumeRole. However, the policy does not include that action. More commonly, the issue is that the policy is missing s3:PutObjectAcl or the bucket policy denies access. But among the options, the most likely is that the policy does not include s3:ListBucket, which is often required for PUT operations? Actually, s3:PutObject does not require ListBucket. However, the typical issue is that the IAM role is not attached to the instance. Option B is correct: The role is not attached to the EC2 instance. Option A is wrong because s3:PutObject is allowed. Option C is wrong because there is no bucket policy shown. Option D is wrong because S3 server-side encryption does not block uploads.
What should I do if I get this SOA-C02 question wrong?
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related SOA-C02 ACL questions on filtering logic and placement.
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?
Standard ACLs match source addresses.
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 SOA-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 SOA-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.