what two scenarios can devices transmit?

In an Ethernet network, under what two scenarios can devices transmit? (Choose two.)

A.
when they receive a special token

B.
when there is a carrier

C.
when they detect no other devices are sending

D.
when the medium is idle

E.
when the server grants access

Explanation:
Ethernet network is a shared environment so all devices have the right to access to the medium. If
more than one device transmits simultaneously, the signals collide and can not reach the
destination.
If a device detects another device is sending, it will wait for a specified amount of time before
attempting to transmit.
When there is no traffic detected, a device will transmit its message. While this transmission is
occurring, the device continues to listen for traffic or collisions on the LAN. After the message is
sent, the device returns to its default listening mode.