What is a valid example of a vSphere Update Manager upgrade?

What is a valid example of a vSphere Update Manager upgrade?

A.
An ESXi 5.x host update with automatically deleted snapshots.

B.
Upgrading an ESX 4.1 host to ESXi 5.x with a sufficent boot partition.

C.
A VMware Tools upgrade on a Fault Tolerant machine with automatic snapshots

D.
Upgrading and patching multiple ESXi hosts simultaneously in a selected cluster.