Which of the following commands correctly mount a CD-ROM drive?

Explanation

Each of the commands listed can be used to mount a CD-ROM drive: specifying the filesystem type explicitly with 'mount -t iso9660 /dev/cdrom /mnt/cdrom', mounting directly from the device with 'mount /dev/cdrom', or mounting using the mount point with 'mount /mnt/cdrom'. Therefore, all these options are correct.