What is the function of the unshareall command when run on an NFS server?

A.
Unshares only the last shared resources.

B.
Unshared all resources listed in the /etc/vfstab file.

C.
Unshares only those resources that are not currently being used.

D.
Unshares all shared resources listed in the /etc/dfs/sharetab file.

E.
Unshares and then re-shares all resources listed in the /etc/dfs/dfstab file.