At a convention, you and others are attempting to exchange electronic business cards between Personal Digital Assistant (PDAs) via serial infrared interfaces. What statements are true about this serial infrared data exchange?

A.
Serial infrared device discovery and negotiation are always performed at 9.6 kbps.

B.
Serial infrared connections can be either point-to-point or point-to-multipoint.

C.
Nearby WLAN and WPAN devices will interfere with infrared serial data exchange.

D.
Communicating devices must support a common data rate in order to transfer data.