What is the purpose of the Pairwise Transient Key (PTK) in IEEE 802.11 Authentication and Key Management?

A.
The GMK, used for encrypting multicast data frames, is derived from the PTK.

B.
The PTK is used to encrypt unicast data frames that traverse the wireless medium.

C.
The PTK is XOR’d with the PSK on the Authentication server to create the AAA key.

D.
The PTK is used to encrypt the Pairwise Master Key (PMK) for distribution to the 802.1X Authenticator during the 4-Way Handshake.

E.
The PTK is combined with a nonce during the 4-Way Handshake to create the GMK.