问题：

[多选]

Refer to the exhibit. Which three statements accurately describe this GLBP topology？ （Choose three.）（）

A .  Router A is responsible for answering ARP requests sent to the virtual IP address.
B .  If Router A becomes unavailable， Router B will forward packets sent to the virtual MAC address of Router A
C .  If another router were added to this GLBP group， there would be two backup AVGs
D .  Router B is in GLBP listen state.
E .  Router A alternately responds to ARP requests with different virtual MAC addresses.
F .  Router B will transition from blocking state to forwarding state when it becomes the AVG