Is it possible to use Change Block Tracking (CBT) with Hyper-V?
A.
No, for Hyper-V hosts a proprietary filtering mechanism is used.
B.
Yes, but only for gen 2 virtual machines using VHDX.
C.
Yes, Veeam Backup & Replication installs a file system filter driver on every host.
D.
Yes, Hyper-V has built-in Change Block Tracking just like vSphere has.