Under which of the circumstances listed below would you perform a server NOS update?

A.
As soon as a new update becomes available.

B.
When there are security flaws that make the server system vulnerable.

C.
All of the above.

D.
None of the above.

Explanation:
When there are security flaws that make the server system vulnerable, you should investigate whether a released update addresses your current security issue, and then plan for updating of the NOS.
Incorrect
Answers:
A: The general rule when it comes to upgrading operating systems on commercial servers is: Do not perform an upgrade if nothing is broken.
C: Option B is the correct answer.
D: Option B is the correct answer.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 430-431.