The correct command for checking and repairing a corrupted filesystem is fsck. It checks the integrity of the filesystem and repairs any errors found when the filesystem is not mounted, which prevents additional corruption or data loss during the repair process. The command e2fsck allows checks only for ext2/ext3/ext4 filesystem types, which might not apply to all filesystems. The mkfs command is used to create a filesystem, not repair it. Using it in this scenario would result in data loss. fdisk is used for disk partitioning, which is not applicable to filesystem checks or repairs.