Which of the following is not true about intrusion detection systems (motion detectors, vibration sensors, light beams)?

A.
They require human response

B.
They cause a lot of false alarms

C.
They depend on a constant power supply

D.
They are foolproof

Explanation:
Intrusion detection systems require someone to respond when they
alarm, are sensitive thus cause many false alarms, and require a constant power
supply. They are not foolproof, nothing is.