While designing the business continuity plan (BCP) for an airline reservation system, the MOST appropriate
method of data transfer/backup at an offsite location would be:

A.
shadow file processing.

B.
electronic vaulting.

C.
hard-disk mirroring.

D.
hot-site provisioning.

Explanation:
In shadow file processing, exact duplicates of the files are maintained at the same site or at a remote site. The
two files are processed concurrently. This is used for critical data files, such as airline booking systems.
Electronic vaulting electronically transmits data either to direct access storage, an optical disc or another
storage medium; this is a method used by banks. Hard-disk mirroring provides redundancy in case the primary
hard disk fails. All transactions and operations occur on two hard disks in the same server. A hot site is an
alternate site ready to take over business operations within a few hours of any business interruption and is not a
method for backing up data.