Which two statements about IPv6 automatic 6to4 tunnels are true? (Choose two)
A. The router at each end of the tunnel must support both IPv4 and IPv6.
B. They support both point-to-point and point-to-multipoint operations.
C. The IPv6 routers that establish automatic 6to4 tunnels are configured in pairs.
D. The IPv4 infrastructure operates as a virtual broadcast mutliaccess link.
E. They support point-to-multipoint operations only.