Which statement about the CAK is true?

A.
It is the master key that generates the other keys that MACsec requires.

B.
Failed MACsec connections fall back to MAB by default.

C.
It is the key that is used to discover MACsec peers and perform key negotiation between the
peers.

D.
It is the secret key that encrypts traffic during the connection.

E.
It is the key that is used to negotiate session encryption keys.