The basic Electronic Access Control (EAC) components required for access doors are an
electromagnetic lock,

A.
A credential reader, and a door closed sensor.

B.
A card reader, and a door open sensor.

C.
A biometric reader, and a door open sensor.

D.
A card reader, and door motion detector.

Explanation:
We have not been able to find any reference to this question really. So we are going with “A
credential reader, and a door closed sensor”. “In addition to smart and dumb cards, proximity
readers can be used to control physical access. A proximity reader can be passive device, a fieldpowered device, or a transponder.” – Ed Tittle CISSP Study Guide (sybex) pg 650