
Explanation

Box 1: Yes
VM1 and VM2 are in an available set named AVSET1.
For all Virtual Machines that have two or more instances deployed in the same Availability Set, we
[Microsoft] guarantee you will have Virtual Machine Connectivity to at least one instance at least 99.95% of the time.
Box 2: No
VM3 and VM4 are in the same availability zone and are in an availability set named AVSET2.
Box 3: Yes
VM5 and VM6 are in different availability zones.
For all Virtual Machines that have two or more instances deployed across two or more Availability Zones in the same Azure region, we [Microsoft] guarantee you will have Virtual Machine Connectivity to at least one instance at least 99.99% of the time.
References:
https://azure.microsoft.com/en-us/support/legal/sla/virtual-machines/v1_8/