Question 1,084 of 1,616
Development with AWS ServicesmediumMultiple ChoiceObjective-mapped

DVA-C02 Development with AWS Services Practice Question

This DVA-C02 practice question tests your understanding of development with aws services. 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.

A developer is deploying a web application using AWS Elastic Beanstalk. The application uses an Amazon RDS MySQL database. The developer wants to ensure that database credentials are not stored in the application code or environment variables. The solution must automatically rotate credentials every 90 days. The developer has created a secret in AWS Secrets Manager containing the database credentials. The Elastic Beanstalk environment is configured with an IAM instance profile that has permission to read the secret. However, when the application is deployed, it fails to connect to the database. The developer checks the application logs and sees a 'Host not found' error. The RDS instance is in a private subnet, and the Elastic Beanstalk environment is in the same VPC. What is the MOST likely cause of the connection failure?

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.

Question 1mediummultiple choice
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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

The application code is not retrieving the secret from Secrets Manager at startup.

Option D is correct. The application likely needs to retrieve the secret at runtime, but the code may be incorrect. However, the 'Host not found' error suggests the database hostname is not being resolved. Option A is wrong because the instance profile has permission. Option B is wrong because Secrets Manager does not automatically inject into environment; the app must fetch it. Option C is wrong because the secret can be stored as plaintext or JSON; format is not the issue.

Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

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 secret is not correctly referenced in the Elastic Beanstalk environment properties.

    Why it's wrong here

    Secrets Manager integration with Elastic Beanstalk is not automatic; the app must retrieve it.

  • The application code is not retrieving the secret from Secrets Manager at startup.

    Why this is correct

    The application must call Secrets Manager to get the credentials; otherwise it tries to connect with undefined values.

    Clue confirmation

    The clue word "most likely" in the question point toward this answer.

    Related concept

    CIDR notation defines the prefix length.

  • The IAM instance profile does not have the necessary permissions to access the secret.

    Why it's wrong here

    The developer says the profile has permission.

  • The secret is stored in a different region than the Elastic Beanstalk environment.

    Why it's wrong here

    No region mismatch mentioned.

Common exam traps

Common exam trap: usable hosts are not the same as total addresses

Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.

Detailed technical explanation

How to think about this question

Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.

KKey Concepts to Remember

  • CIDR notation defines the prefix length.
  • Block size helps identify subnet boundaries.
  • Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
  • The required host count determines the smallest suitable subnet.

TExam Day Tips

  • Write the block size before choosing the subnet.
  • Check whether the question asks for hosts, subnets or a specific address range.
  • Do not confuse /24, /25, /26 and /27 host counts.

Key takeaway

Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

Real-world example

How this comes up in practice

A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.

What to study next

Got this wrong? Here's your next step.

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related DVA-C02 subnetting questions on CIDR, address ranges, and subnet selection.

Related practice questions

Related DVA-C02 practice-question pages

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FAQ

Questions learners often ask

What does this DVA-C02 question test?

Development with AWS Services — This question tests Development with AWS Services — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: The application code is not retrieving the secret from Secrets Manager at startup. — Option D is correct. The application likely needs to retrieve the secret at runtime, but the code may be incorrect. However, the 'Host not found' error suggests the database hostname is not being resolved. Option A is wrong because the instance profile has permission. Option B is wrong because Secrets Manager does not automatically inject into environment; the app must fetch it. Option C is wrong because the secret can be stored as plaintext or JSON; format is not the issue.

What should I do if I get this DVA-C02 question wrong?

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related DVA-C02 subnetting questions on CIDR, address ranges, and subnet selection.

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?

CIDR notation defines the prefix length.

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Last reviewed: Jun 20, 2026

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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.