Which system files are updated as devices are mounted and unmount to provide information on the mounted devices and the options used?

Which system files are updated as devices are mounted and unmount to provide information on the
mounted devices and the options used? (Please specify TWO answers)

A.
/proc/dtab

B.
/etc/mtab

C.
/etc/fstab

D.
/proc/mounts

E.
/proc/devices

Explanation:
The programs mount and umount maintain a list of currently mounted file systems in the file
/etc/mtab. If no arguments are given to mount, this list is printed.
See
http://linux.web.cern.ch/linux/scientific5/docs/rhel/Deployment_Guide/s2-proc-mounts.html
Similar to the contents of /etc/mtab, except that /proc/mount is more up-to-date.