Answer:
B. /etc/fstab file.
Explanation:
The /var/filesystem file is a subdirectory of the root directory of a linux operating system, used to store files during the operation of a computer system.
The /boot/config file is a file directory used to store system configuration parameters which can be accessed by the GPU before the installation of the ARM CPU and linux.
The /etc/mount (or /etc/mtab) and /etc/fstab are used to show the list of mounted volumes. The /etc/mtab gives details of already mounted volumes, but the /etc/fstab shows the list of possible volumes to be mounted upon the boot of the system.
