A storage device is a hardware device that is used to store and retrieve digital information. Out of the given options, a diskette is a storage device. A diskette, also known as a floppy disk, is a thin, flexible magnetic disk that is used for data storage. It is inserted into a disk drive, which reads and writes data to the disk. Diskettes were commonly used in the past for storing small amounts of data, such as documents, pictures, and programs.