The following ZFS file system is available on your system:
NAME USED AVAIL REFER MOUNTPOINT
files 82K 72.8G 24.5K /data
You want to temporarily unmount the /data file system.
Which set of commands will unmount the /data file system so that it is not available to users and then mount the system when you are ready to make it available again?

A.
umount /data -to unmount the file system; mount /data to mount the file system.

B.
zfs unmount /data -to unmount the file system; zfs mount -a to mount the file system.

C.
zfs umount /data -to unmount the file system; zfs mount /data to mount the file system.

D.
zfs unmount /data -to unmount the file system; zfs mount /data to mount the file system.