The cat /proc/mdstat command is the correct option because it provides the current status of all active software RAID arrays, including information on individual disks and their state within each array. The mdadm --detail command also gives detailed information, but it needs to be followed by a specific device name (e.g., mdadm --detail /dev/md0), and therefore it is not as comprehensive for displaying all active arrays at once. The fdisk -l command lists all partition tables, which is not specific to active RAID arrays. The lsblk command lists block devices, which includes RAID arrays, but does not provide detailed RAID status.