Availability makes information accessible by protecting from each of the following except:

A.
Denial of services

B.
Fires, floods, and hurricanes

C.
Unreadable backup tapes

D.
Unauthorized transactions

Explanation:
D: Availability is the principle that information is available and accessible by users when needed. The two primary areas affecting the availability of systems are (1) denial of service attacks and (2) loss of service due to a disaster, which could be man-made or natural. Page 410.