This ANS-C01 practice question tests your understanding of network design. 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 company has a VPC with multiple subnets across two Availability Zones. They are designing a highly available web application using an Application Load Balancer (ALB) and EC2 instances in an Auto Scaling group. Which of the following is the most resilient and cost-effective design for the network layer?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Deploy a single ALB with subnets in two AZs and enable cross-zone load balancing.
Option C is correct because deploying a single Application Load Balancer (ALB) with subnets in two Availability Zones (AZs) and enabling cross-zone load balancing provides high availability and fault tolerance at the network layer. The ALB automatically distributes incoming traffic across healthy targets in all enabled AZs, eliminating the need for multiple load balancers and reducing costs while maintaining resilience. This design leverages the ALB's native ability to handle AZ failures by routing traffic only to healthy AZs, making it both resilient and cost-effective.
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.
✗
Deploy a Network Load Balancer (NLB) in each AZ and associate them with a single ALB.
Why it's wrong here
This adds complexity and cost; an ALB alone is sufficient.
✗
Deploy an ALB in one AZ and EC2 instances in the same AZ.
Why it's wrong here
This is not highly available if the AZ fails.
✓
Deploy a single ALB with subnets in two AZs and enable cross-zone load balancing.
Why this is correct
Cross-zone balancing ensures traffic is distributed across instances in all AZs.
Related concept
Read the scenario before looking for a memorised answer.
✗
Deploy an ALB in each AZ and use Route 53 weighted routing.
Why it's wrong here
An ALB is regional; deploying per AZ is unnecessary and costly.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume deploying a load balancer in each AZ (Option D) is necessary for high availability, but they overlook that a single ALB with subnets in multiple AZs and cross-zone load balancing already provides full AZ-level redundancy at lower cost and complexity.
Detailed technical explanation
How to think about this question
Under the hood, an ALB with cross-zone load balancing enabled distributes incoming traffic evenly across all registered targets in all enabled AZs, regardless of which AZ the traffic arrives at. This is achieved by the ALB nodes in each AZ maintaining connections to targets in all AZs, which improves utilization and reduces the risk of uneven load distribution during AZ failures. In a real-world scenario, if one AZ becomes impaired, the ALB automatically reroutes traffic to healthy targets in the remaining AZs without manual intervention, ensuring continuous availability while minimizing costs by using a single load balancer.
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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
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.
Network Design — This question tests Network Design — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Deploy a single ALB with subnets in two AZs and enable cross-zone load balancing. — Option C is correct because deploying a single Application Load Balancer (ALB) with subnets in two Availability Zones (AZs) and enabling cross-zone load balancing provides high availability and fault tolerance at the network layer. The ALB automatically distributes incoming traffic across healthy targets in all enabled AZs, eliminating the need for multiple load balancers and reducing costs while maintaining resilience. This design leverages the ALB's native ability to handle AZ failures by routing traffic only to healthy AZs, making it both resilient and cost-effective.
What should I do if I get this ANS-C01 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 ANS-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 ANS-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.