You have just configured the adjacent side of an EtherChannel from the console and receive the message in the following exhibit. What is the problem?

A. One of the switches is configured with on mode and the other with desirable mode.
B. One of the switches is configured with auto mode and the other with desirable mode.
C. One of the switches is configured with active mode and the other with active mode.
D. One of the switches is configured with passive mode and the other with passive mode

A. When one side is configured with on mode, it uses no control protocol. If a control protocol is sensed from the adjacent switch, the port will enter err-disable mode to protect it from a loop.