The correct actions are to launch EC2 instances in at least two Availability Zones and to configure the Application Load Balancer as internet-facing while registering those instances from multiple AZs. This design ensures high availability across multiple AZs with ALB because if one Availability Zone fails, the load balancer automatically reroutes traffic to healthy instances in the remaining zones, eliminating a single point of failure. On the AWS Certified Solutions Architect Professional SAP-C02 exam, this scenario tests your understanding of fault-tolerant architecture patterns, specifically the requirement that both the compute layer and the load balancer must be multi-AZ aware. A common trap is thinking that an internal ALB or a single-AZ deployment can achieve true high availability—they cannot, because the load balancer itself must be resilient across zones. Memory tip: think “two zones, one ALB, all traffic flows” to remember that both the instances and the ALB configuration must span multiple AZs for full fault tolerance.
SAP-C02 Design for New Solutions Practice Question
This SAP-C02 practice question tests your understanding of design for new solutions. 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 company is designing a new application that will run on Amazon EC2 instances behind an Application Load Balancer (ALB). The application must be highly available and fault-tolerant across multiple Availability Zones. Which TWO actions should be taken to achieve this? (Choose two.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Launch EC2 instances in at least two Availability Zones.
Option C is correct because launching EC2 instances in at least two Availability Zones (AZs) ensures that if one AZ fails, the application continues to run from the other AZ, providing fault tolerance and high availability. Option D is correct because configuring the ALB to be internet-facing and registering instances from multiple AZs allows the ALB to distribute incoming traffic across healthy instances in different AZs, automatically rerouting traffic if an AZ becomes impaired.
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.
✗
Use an Auto Scaling group to launch instances only in one Availability Zone.
Why it's wrong here
Auto Scaling should span multiple AZs for high availability.
✗
Use a Network Load Balancer instead of ALB for better performance.
Why it's wrong here
NLB is for TCP/UDP; ALB is appropriate for HTTP applications.
✓
Launch EC2 instances in at least two Availability Zones.
Why this is correct
Multiple AZs provide fault tolerance if one AZ fails.
Related concept
Read the scenario before looking for a memorised answer.
✓
Configure the ALB to be internet-facing and register instances from multiple AZs.
Why this is correct
ALB distributes traffic across healthy instances in multiple AZs.
Related concept
Read the scenario before looking for a memorised answer.
✗
Launch all EC2 instances in a single Availability Zone for low latency.
Why it's wrong here
Single AZ is not fault-tolerant.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often think a single AZ with Auto Scaling is sufficient for high availability, but true fault tolerance requires distributing resources across multiple AZs to survive an AZ-level failure.
Detailed technical explanation
How to think about this question
Under the hood, an ALB uses a regional endpoint and automatically scales its nodes across AZs; registering instances from multiple AZs enables the ALB to perform cross-zone load balancing, which distributes traffic evenly and reduces the impact of an AZ failure. In a real-world scenario, if an AZ experiences a power outage, the ALB's health checks mark instances in that AZ as unhealthy and route traffic only to healthy instances in other AZs, ensuring continuous availability without manual intervention.
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
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
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.
Design for New Solutions — This question tests Design for New Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Launch EC2 instances in at least two Availability Zones. — Option C is correct because launching EC2 instances in at least two Availability Zones (AZs) ensures that if one AZ fails, the application continues to run from the other AZ, providing fault tolerance and high availability. Option D is correct because configuring the ALB to be internet-facing and registering instances from multiple AZs allows the ALB to distribute incoming traffic across healthy instances in different AZs, automatically rerouting traffic if an AZ becomes impaired.
What should I do if I get this SAP-C02 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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is designing a new web application that will run on Amazon EC2 instances behind an Application Load Balancer. The application must be highly available across multiple Availability Zones. Which TWO actions should the architect take? (Choose TWO.)
easy
A.Launch all EC2 instances in a single Availability Zone.
✓ B.Configure the ALB as internet-facing and attach it to multiple Availability Zones.
✓ C.Launch EC2 instances in at least two Availability Zones.
D.Use a Network Load Balancer instead of an Application Load Balancer.
E.Assign Elastic IP addresses to each EC2 instance.
Why B: For high availability, the ALB must be internet-facing (option B) and EC2 instances should be in multiple AZs (option C). Option A (single AZ) is not HA. Option D (NLB) is not needed. Option E (public IPs) is unnecessary.
Last reviewed: Jun 24, 2026
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This SAP-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 SAP-C02 exam.
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