In which case will a BIOS upgrade not necessarily be required?

A.
Installing a incompatible Hard drive

B.
Installing a incompatible RAID controller

C.
Installing a incompatible processor

D.
Installing compatible RAM

Explanation:
When installing peripherals that are compatible you are less likely to run into trouble.
Incorrect Answers:
A: This would be detected and would have been put in use already and does not require a BIOS upgrade.
B: This would be detected and would have been put in use already and does not require a BIOS upgrade.
C: This would be detected and would have been put in use already and does not require a BIOS upgrade.
Reference:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 391.