Which of the following concepts describes the process of adding hard drives to a server system?

A.
Scaling out

B.
Scaling down

C.
Scaling up

D.
None of the above

Explanation:
Scaling up is the concept used to refer to the adding of hard drives to a server system.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 383-384.