In order to enhance worker productivity， a Cisco wireless network has been implemented at all    locations.  Which three statements regarding WLAN are true？（）

• A、A WLAN client will operate in half-duplex mode.
• B、The Aironet 1230 access point is an example of an access point that operates solely as a lightweight access point.
• C、Ad hoc mode allows mobile clients to connect directly without an intermediate AP.
• D、WLANs are designed to share the medium and can easily handle an increased demand of channel contention.
• E、A lightweight AP receives control and configuration from a WLAN controller to which it is associated.
• F、Another term for infrastructure mode is independent service set （IBSS）.