The /prod/inv file system needs to be unmounted so you can take it offline for maintenance. When
you try and unmount it, you receive the following error message:
umount: /prod/inv busy
One or more users are still using it.
Which command should you use to discover who is using the file system?
A.
who -q
B.
fuser -cu /prod/inv
C.
who /prod/inv
D.
fuser -ck /prod/inv
Explanation: