If it was said that was a low voltage condition over a short period of time, which of the following has occurred?

A.
A spike

B.
A surge.

C.
Sags

D.
Brownouts

Explanation:
Sag is a low voltage condition for a short period of time.
Incorrect Answers:
A: A spike is a very high voltage level-usually twice the normal voltage B: A surge is a voltage increase (10 or 20 volts above normal) that occurs over a longer period of time D: Brownouts occur over longer periods of time (several seconds or longer).
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 227-240.