The installation of which server components will make the server more fault-tolerant?

A.
A second hard disk drive.

B.
An additional RAM module.

C.
A power supply with a higher Watt rating.

D.
A redundant Network Interface Card (NIC).

Explanation:
A second, redundant NIC will improve a server’s fault tolerance as it will remain available even in the event of a failure of one of the network interface cards.
Incorrect
Answers:
A: Simply installing a second hard drive will not improve fault tolerance, unless the hard drives are configured for mirroring.
B: Adding more RAM will improve server performance but won’t improve fault tolerance.
C: A bigger power supply won’t improve fault tolerance as the server will still fail should the power supply fail.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 39-45.