Final answer:
The DVD-Rom option potentially provides the most backup space.
Step-by-step explanation:
The option that potentially provides the most backup space for data from a hard drive is d) DVD-Rom. DVD-R disks typically have a storage capacity of 4.7 GB to 9 GB, whereas floppy disks only have a capacity of 1.44 MB, CD-Roms have a capacity of about 700 MB, and USB devices can range from a few gigabytes to several terabytes.