Which two NFS Protocol versions does vSphere 6 support?

Which two NFS Protocol versions does vSphere 6 support? (Choose two.)

A.
Version 3

B.
Version 3.1

C.
Version 4

D.
Version 4.1

Explanation:
ESXi supports NFS protocols version 3 and 4.1. To support both versions, ESXi uses two different NFS clients.
https://pubs.vmware.com/vsphere-60/index.jsp?topic=%2Fcom.vmware.vsphere.storage.doc%2FGUID-8A929FE4-1207-4CC5-A086-
7016D73C328F.html