You have just added a CD.ROM drive (/dev/hdd) to your system and have added it to yourfstab. Typically you can use which of the following commands to mount media in that drive to /mnt/cdrom?

`mount /dev/cdrom /mnt/cdrom` would work if `/dev/cdrom` were the device, but the question specifies `/dev/hdd` and implies `fstab` setup.

`mount /dev/cdrom` is incomplete as it doesn't specify a mount point.

`mount -t cdrom /dev/cdrom /mnt/cdrom` specifies a filesystem type and device, which is unnecessary if already defined in `fstab`, and uses `/dev/cdrom` not `/dev/hdd`.

D is correct because if `/dev/hdd` is properly configured in `/etc/fstab` with `/mnt/cdrom` as its mount point, the `mount` command can simply be invoked with the mount point (e.g., `mount /mnt/cdrom`). The `mount` utility will then look up the details in `/etc/fstab` and mount the specified device (`/dev/hdd`) to that location.

`automount` is typically for network filesystems or hot-pluggable devices with an automounter service, not a direct command for a simple `fstab` entry.