Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A developer needs to grant an IAM role in Account B read-only access to objects in an S3 bucket in Account A. The bucket is encrypted with server-side encryption using AWS KMS (SSE-KMS) with a customer managed key (CMK) in Account A. Which combination of policies is required for the cross-account access to succeed?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
The bucket policy in Account A grants s3:GetObject to the role, the KMS key policy grants kms:Decrypt to the role, and the role in Account B has an IAM policy allowing s3:GetObject and kms:Decrypt
All three policies are required: bucket policy and key policy in Account A grant the necessary permissions, and the IAM role in Account B must have the corresponding IAM policy to authorize the use of those grants.
B
Distractor review
The bucket policy in Account A grants s3:GetObject to the role, and the role in Account B has an IAM policy allowing s3:GetObject. No KMS permissions are needed because SSE-KMS uses AWS managed keys by default.
The question specifies a customer managed key, which requires explicit key policy grants. AWS managed keys cannot be used in cross-account scenarios.
C
Distractor review
The bucket policy in Account A grants s3:GetObject to the role, and the KMS key policy grants kms:Decrypt to the role. The role in Account B does not need additional IAM policies because the bucket and key policies provide sufficient permissions.
IAM roles require IAM policies to authorize actions, even if resource-based policies grant access. The role must have an IAM policy allowing s3:GetObject and kms:Decrypt.
D
Distractor review
Only the bucket policy in Account A needs to grant s3:GetObject to the role. KMS is not involved because the bucket is encrypted with SSE-KMS but the role can decrypt using the default KMS key.
SSE-KMS with a customer managed key requires explicit KMS permissions. The default key (AWS managed key) cannot be used for cross-account access.
Common exam trap
Common exam trap: NAT rules depend on direction and matching traffic
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.
Technical deep dive
How to think about this question
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.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A developer is building a REST API using Amazon API Gateway that will serve static content from an Amazon S3 bucket. The API should cache responses for frequently accessed objects to reduce latency. Which API Gateway feature should the developer enable?
Question 2
A developer is running a web application on multiple Amazon EC2 instances behind an Application Load Balancer (ALB). The application needs to store user session state that must be available across all instances. The session data is small and temporary but must survive individual instance failures. Which AWS service should the developer use to store this session state?
Question 3
A developer has an AWS Lambda function that processes messages from an Amazon SQS standard queue. The function is idempotent and currently has a batch size of 10. The developer wants to increase throughput and increases the batch size to 100. After the change, CloudWatch metrics show a significant increase in throttles and the queue backlog is growing. The function's reserved concurrency is set to 10. What is the most effective action to resolve the throttling and improve throughput?
Question 4
A developer is managing an application running on Amazon EC2 instances behind an Application Load Balancer. Users report that the application becomes unresponsive after several hours, and restarting the instance temporarily fixes the issue. The developer suspects a memory leak but cannot add custom instrumentation. Which AWS service can collect memory utilization metrics and help identify the memory leak with minimal configuration?
Question 5
A developer is building a serverless web application using AWS Lambda and Amazon DynamoDB. The application needs to perform complex aggregations on data stored in DynamoDB. Which AWS service should the developer use to perform these aggregations efficiently without reading all the data into Lambda?
Question 6
A developer has an Amazon S3 bucket containing private user documents. The application must generate a time-limited URL for users to download their own documents without requiring the users to have AWS credentials. Which solution should the developer use?
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: The bucket policy in Account A grants s3:GetObject to the role, the KMS key policy grants kms:Decrypt to the role, and the role in Account B has an IAM policy allowing s3:GetObject and kms:Decrypt — Cross-account access to SSE-KMS encrypted S3 objects requires three sets of permissions: (1) The S3 bucket policy in Account A must explicitly grant s3:GetObject to the IAM role in Account B. (2) The KMS key policy in Account A must grant kms:Decrypt to the IAM role in Account B. (3) The IAM role in Account B must have an IAM policy that allows s3:GetObject and kms:Decrypt. Without all three, access will be denied. Customer managed keys require explicit key policy grants; AWS managed keys do not allow cross-account access.
What should I do if I get this DVA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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