Given the following information, why is an error returned when trying to unmount the fitesystem
/var/logs/tsm?

A.
The child filesystem /var/logs/tsm/livelog is still mounted.

B.
The hd8 is still tied to the filesystem.

C.
The filesystem is of type mount=true so cannot be unmounted while the system is running

D.
The umount command is being run while inside the filesystem.

Explanation: