You have an Azure subscription that contains a virtual machine named VM1 as shown in...

A managed disk can only be attached to a virtual machine that is in the exact same Azure region as the disk, and if the disk is pinned to a specific availability zone, it can only attach to a VM running in that same zone; a disk with no zone assignment (a regional, non-zonal disk) can attach to a VM in any zone within that region. The resource group a disk belongs to is irrelevant to attachment eligibility, since disks and virtual machines are independent resources that do not need to share a resource group. VM1 is in East US, zone 1. Disk1 is in East US with no zone assigned, so, being non-zonal, it can attach to any VM in East US regardless of zone, including VM1. Disk2 is in East US and is pinned to zone 1, which matches VM1 ' s zone exactly, so it can also attach, even though it sits in a different resource group (RG2). Disk3 and Disk4 are both in Central US, a different region from VM1 ' s East US, which alone disqualifies both of them regardless of their zone settings. Because only Disk1 and Disk2 satisfy the region (and, where applicable, zone) requirements, the correct answer is Disk1 and Disk2 only.