A prolonged power supply that is below normal voltage is a:

A.
brownout

B.
blackout

C.
surge

D.
fault

Explanation:
A prolonged power supply that is below normal voltage is a brownout.
HARRIS, Shon, All-In-One CISSP Certification Exam Guide, 3rd. Edition McGrawHill/Osborne,
2005, page 368.