Scaling up provides ______.

A.
failover

B.
fault-tolerance

C.
improved performance

D.
all of the above

Explanation:
Scaling up is the process of adding components or upgrading existing components in a server and provides improved server performance.
Incorrect
Answers:
A: Failover is the process in which a secondary system assumes the duties of a primary system should the primary system fail. This requires additional servers, rather than additional components.
B: Fault-tolerance is provided by adding additional, redundant components, such as a second NIC, to a server to eliminate a single point of failure on the system. However, adding components or upgrading existing components does not improve fault-tolerance.
D: Scaling up does not provide fault-tolerance or failover.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 39-45.