Authentication for user data traffic is important, but so is authentication for IP voice traffic. The Cisco 830 802.1 feature provides an easier method for allowing IP voice traffic through the VPN, because it（）.

• A、requires access lists to identify the voice traffic 
• B、can allow traffic from a device without 802.1X authentication, by MAC address
• C、can allow traffic from Cisco IP phones by listening to their CDP advertisements
• D、allows all packets marked with a ToS of 5 to bypass authentication
• E、allows all IP voice packets to bypass authentication via stateful inspection