________________________ provides continuous online backup functionality. It combines hard disk technology with the cheaper and slower optical or tape jukeboxes.

A.
Storage area network

B.
Hierarchical storage management

C.
Redundant array of independent tapes

D.
Massive array of inactive disks

Explanation:
HSM (Hierarchical Storage Management) provides continuous online backup
functionality. It combines hard disk technology with the cheaper and slower optical
or tape jukeboxes. The HSM system dynamically manages the storage and recovery of
files, which are copied to storage media devices that vary in speed and cost. The
faster media holds the data that are accessed more often, and the seldom-used files
are stored on the slower devices, or near-line devices.