Question 13 of 981
AZ-900 Describe cloud concepts Practice Question
A company deploys their application across multiple availability zones in an Azure region. This is done to improve which aspect of the application?
⚠ Common exam trap
Candidates often confuse high availability with scalability or elasticity, mistakenly thinking that distributing across zones helps handle more users or automatically adjust capacity, when in fact it is solely about maintaining uptime during failures.
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
✓
High availability
Deploying an application across multiple availability zones within an Azure region ensures that if one zone experiences an outage (e.g., due to power failure or network disruption), the application can continue serving traffic from the remaining zones. This architecture directly improves high availability by eliminating a single point of failure at the datacenter level, typically achieving a service-level agreement (SLA) of 99.99% for virtual machines when using two or more instances across zones.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Scalability
Why it's wrong here
Scalability is about handling increased load, not fault tolerance.
When this WOULD be correct
A question asking: 'A company adds more virtual machines to handle increased traffic during peak hours. This is an example of improving which aspect?' — here, scalability would be correct because it directly addresses the ability to handle growing workloads.
- ✗
Elasticity
Why it's wrong here
Elasticity is about automatic scaling based on demand.
When this WOULD be correct
A question asking: 'Which feature allows an application to automatically scale resources up or down based on demand?' would make elasticity correct, as it refers to dynamic resource adjustment.
- ✓
High availability
Why this is correct
Availability zones improve uptime by isolating failures.
- ✗
Cost efficiency
Why it's wrong here
Using multiple zones may increase cost, it is not primarily about cost efficiency.
When this WOULD be correct
A question asking: 'A company moves their application from a single large VM to multiple smaller VMs that automatically scale based on demand. This is done to improve which aspect?' — here, cost efficiency could be correct if the scenario emphasizes paying only for used resources and reducing waste.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-900 exam frequently reuses these exact scenarios with slightly different constraints.
✓High availabilityCorrect answer▾
Why this is correct
Availability zones improve uptime by isolating failures.
✗ScalabilityWrong answer — click to see why▾
Why this is wrong here
Deploying across multiple availability zones does not inherently improve scalability; it improves fault tolerance and uptime. Scalability is about handling increased load, typically achieved through horizontal scaling (adding more instances) or vertical scaling (increasing resources), not by distributing across zones.
★ When this WOULD be the correct answer
A question asking: 'A company adds more virtual machines to handle increased traffic during peak hours. This is an example of improving which aspect?' — here, scalability would be correct because it directly addresses the ability to handle growing workloads.
Why candidates choose this
Candidates may confuse high availability with scalability because both involve multiple instances, but they serve different purposes: availability ensures uptime, while scalability ensures performance under load.
✗ElasticityWrong answer — click to see why▾
Why this is wrong here
Deploying across multiple availability zones primarily protects against zone-level failures, improving availability, not the ability to automatically adjust resources (elasticity).
★ When this WOULD be the correct answer
A question asking: 'Which feature allows an application to automatically scale resources up or down based on demand?' would make elasticity correct, as it refers to dynamic resource adjustment.
Why candidates choose this
Candidates confuse elasticity with high availability because both involve distributing resources across zones, but elasticity focuses on scaling, not fault tolerance.
✗Cost efficiencyWrong answer — click to see why▾
Why this is wrong here
Deploying across multiple availability zones increases redundancy and fault tolerance, directly improving high availability, not cost efficiency. In fact, using multiple zones typically increases costs due to additional resources and data transfer.
★ When this WOULD be the correct answer
A question asking: 'A company moves their application from a single large VM to multiple smaller VMs that automatically scale based on demand. This is done to improve which aspect?' — here, cost efficiency could be correct if the scenario emphasizes paying only for used resources and reducing waste.
Why candidates choose this
Candidates may confuse high availability with cost efficiency, thinking that distributing workloads reduces costs, but the primary goal of availability zones is resilience, not cost savings.
Analysis generated from the official AZ-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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Last reviewed: Jun 11, 2026
This AZ-900 practice question is part of Courseiva's free Microsoft 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 AZ-900 exam.
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