Before changing a managed data disk on a production VM, you want a point-in-time copy that you can keep and restore later if needed. What should you create?

An availability set

An availability set improves service availability, but it does not create a copy of a disk for rollback purposes.

A load balancer backend pool

A backend pool distributes traffic to VMs, but it does not preserve disk contents or create recovery copies.

A resource lock

A lock can prevent deletion or modification, but it does not capture data in a point-in-time disk image.

What does this AZ-104 question test?

Read the scenario before looking for a memorised answer.

What is the correct answer to this question?

The correct answer is: A managed disk snapshot — A managed disk snapshot is the best choice because it creates a point-in-time copy of the disk before you make changes. This is a common administrative safety step when modifying data disks, testing changes, or preparing for a rollback. If the update goes badly, you can use the snapshot to create a new disk and recover the previous state without affecting the running VM unless you choose to attach it. Why others are wrong: An availability set is about uptime, not backup. A load balancer backend pool handles network traffic distribution and has nothing to do with disk recovery. A resource lock protects resources from accidental changes, but it does not preserve the current disk state. The only option that actually gives you a reusable copy of the disk is a snapshot.

What should I do if I get this AZ-104 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.