What is true about a 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: 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 have a receiver, transmitter, and battery. The reader sends signals to the card to request information. The card sends the reader an access code.