Which statement about the Lightweight Access Point Protocol （LWAPP） is true？ （）
- A LWAPP encrypts both control traffic and user data.
- B LWAPP encrypts user traffic with an x.509 certificate using AES-CCMP.
- C When set to Layer 3， LWAPP uses a proprietary protocol to communicate with the Cisco Aironet APs.
- D LWAPP encrypts control traffic between the AP and the controller.
- E None of the other alternatives apply.