Which of the following is TRUE with regards to RAID?

A.
RAID is required to ensure zero downtime from power supply failures.

B.
RAID allows you to removal and replacement of a PCI card.

C.
RAID allows you to removed or added drives to a system while the system is still operating.

D.
None of the above.

Explanation:
RAID allows for continued hard drive access in cases of single drive failures, and increases the fault-tolerant capabilities in a drive array.
Incorrect Answers
A: Two or more redundant power supplies are required to ensure zero downtime from power supply failures.
B: Hot-plug PCI cards allows you to removal and replacement of a PCI card while the system is in operation.
C: Hot-plug hard drives can be removed or added to a system while the system is still operating.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 355.