Exam AZ-104 topic 1 question 16 discussion

C is correct

All this means is that the change in hardware was supported by whatever the availability set was running on, not that the question is depricated. If your VM(s) are deployed using the Resource Manager (ARM) deployment model and you need to change to a size which requires different hardware then you can resize VMs by first stopping your VM, selecting a new VM size and then restarting the VM. If the VM you wish to resize is part of an availability set, then you must stop all VMs in the availability set before changing the size of any VM in the availability set. The reason all VMs in the availability set must be stopped before performing the resize operation to a size that requires different hardware is that all running VMs in the availability set must be using the same physical hardware cluster. Therefore, if a change of physical hardware cluster is required to change the VM size then all VMs must be first stopped and then restarted one-by-one to a different physical hardware clusters.

But the question reported: "You try to resize one of the VMs, which returns an allocation failure message." so you can only stop all the 3 vms

I was wondering this too. Chat GPT said this: If you want to add the VM back into the availability set after resizing, this is not directly supported. You would need to delete the VM (keeping its disks) and recreate it within the availability set, which involves downtime and additional configuration.