Which version of NFS does ESX Server require?

A.
version 3 over UDP

B.
version 3 over TCP

C.
version 2 over UDP

D.
version 2 over TCP

Explanation:
ESX Configuration Guide ESX 4.0, vCenter Server 4.0, Page 73.
The NFS client built into ESX uses Network File System (NFS) protocol version 3 to
communicate with the NAS/NFS servers
At the time of introduction of Version 3, vendor support for TCP as a transport-layer
protocol began increasing. While several vendors had already added support for NFS
Version 2 with TCP as a transport, Sun Microsystems added support for TCP as a
transport for NFS at the same time it added support for Version 3. Using TCP as a
transport made using NFS over a WAN more feasible