The following statement about CSMA / CD is correct ______ . (Multiple choices)

The following statement about CSMA / CD is correct ______ . (Multiple choices)
A . CSMA / CD is used in bus-type Ethernet, mainly to solve the problem of how to detect conflicts and ensure the orderly transmission of data when multiple stations send data simultaneously.
B . When a station connected to the Ethernet wants to transmit a frame, it must wait until the channel is idle, ie the carrier disappears.
C . The station can only start transmitting its frames when the channel is idle.
D . If two stations start transmitting at the same time, they will hear the collision of signals and suspend the transmission of frames.

Answer: ABCD