What is true about a physical access control transponder?

A.
It is a card that can be read without sliding it through a card reader.
B.
It is a passive proximity device.
C.
It is a card that a user swipes through a card reader to gain access to a facility.
D.
It exchanges tokens with an authentication server.
Explanation:
A transponder is a type of physical access control device that does
not require the user to slide a card through a reader. The reader and card
communicate directly. The card and reader has a receiver, transmitter, and battery.
The reader sends signals to the card to request information. The card sends the
reader an access code.