Box 1: Yes -
The DNS zone uses the Public IP address of vm1.
Box 2: Yes -
Fabrikam.com is a Private DNS zone. The private IP address is used.
Note: The Azure DNS private zones auto registration feature manages DNS records for virtual machines deployed in a virtual network. When you link a virtual network with a private DNS zone with this setting enabled, a DNS record gets created for each virtual machine deployed in the virtual network.
For each virtual machine, an A record and a PTR record are created. DNS records for newly deployed virtual machines are also automatically created in the linked private DNS zone.
Note: If you use Azure Provided DNS then appropriate DNS suffix will be automatically applied to your virtual machines. For all other options you must either use
Fully Qualified Domain Names (FQDN) or manually apply appropriate DNS suffix to your virtual machines.
Box 3: Yes -
Reference:
https://docs.microsoft.com/en-us/azure/dns/dns-zones-records
https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-name-resolution-for-vms-and-role-instances