Given the following output from /etc/fstab, which filesystems will be automatically checked on boot by the fsck command? /dev/sda1 / ext4 defaults 1 1 none /dev/pts devpts gid=5,mode=620 1 0 none /proc proc defaults 0 1 none /dev/shm tmpfs defaults 1 0 /dev/sdc2 swap swap defaults 0 1 /dev/dvd /media/dvd iso9660 noauto, ro 0 0 a. none, as fsck must be run manually for each filesystem b. /, /dev/pts, and /dev/shm c. /, /proc, and swap d. all of them, as fsck is run automatically at boot for all filesystems