Concept:Comparing typical storage capacities of common storage devices.
Explanation:A compact disk usually holds about 700 MB.
A digital versatile disc (DVD) holds about 4.7 GB and can store more than a CD.
A floppy disk holds only about 1.44 MB, so it has the smallest capacity.
A hard disk can store hundreds of gigabytes or even terabytes, which is far larger than a CD, DVD, or floppy disk.
Therefore, the hard disk has the largest storage capacity.
Answer:D. Hard disk.