A mission-critical virtual machine built on vSphere 4.1 needs to be moved to an ESXi 6.x host.
Which virtual hardware version is needed to move the virtual machine without upgrading?

A.
6

B.
7

C.
10

D.
11

Explanation:
You need version 7 to upgrade a VM on vSphere 4.1 to ESXi 6.x host
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003746