Explanation:
Box 1: Azure Backup for virtual machines
The deployment of App1 to Prod will use shared disks on the virtual machines.
Ensure that the virtual machines in Prod are backed up every four hours.
If you require application-consistent backup of virtual machine including the data disks, or an option to restore an entire virtual machine from backup, restore a file or folder, or restore to a secondary region, then use the Azure VM backup solution Note: Azure Backup offers side-by-side support for backup of managed disks using Disk Backup in addition to Azure VM backup solutions. This is useful when you need once-a-day application consistent backups of virtual machines and also more frequent backups of OS disks or a specific data disk that are crash consistent, and don't impact the production application performance.
Box 2: Managed snapshots
The deployment of App1 to Dev will use multiple disks on each virtual machine.
Ensure that the virtual machines in Dev support up to three on-demand backups per hour.
Reference:
https://learn.microsoft.com/en-us/azure/backup/backup-azure-vms-introduction
https://learn.microsoft.com/en-us/azure/backup/disk-backup-overview