What occurs to the cluster and these VMs during an AHV upgrade?

A Nutanix cluster is equipped with four nodes. Four VMs on this cluster have been configured with a VM-VM anti-affinity policy and are each being hosted by a different node.

What occurs to the cluster and these VMs during an AHV upgrade?
A . One node hosts two VMs while the node being upgraded is in maintenance mode.
B . One VM out of the four powers down when the node hosting it reboots.
C . The AHV pre-upgrade checks fail until the administrator disables the anti-affinity policy.
D . The AHV pre-upgrade checks fail until the four VMs are powered off.

Answer: C