Which of these statements best describes VPLS？（）

• A、 Neither broadcast nor multicast traffic is ever flooded in VPLS.
• B、 Multicast traffic is flooded but broadcast traffic is not flooded in VPLS.
• C、 VPLS emulates an Ethernet switch， with each EMS being analogous to a VLAN.
• D、 Because U-PE devices act as IEEE 802.1 devices， the VPLS core must use STP.
• E、 When the provider experiences an outage， IP re-routing restores PW connectivity and MAC re-learning is needed.