Which two statements are true about the router configuration?

Refer to the exhibit.

Which two statements are true about the router configuration? (Choose two.)

A.
This configuration allows applications on the same segment to communicate via IPv4 or IPv6.

B.
This configuration is referred to as a dual-stack 6to4 tunnel.

C.
This configuration is referred to as a dual stack.

D.
This configuration will attempt to route packets using IPv4 first, and if that fails, then IPv6.

Explanation:
This router demonstrates an example of an IPv6 Dual Stack configuration. Dual
stack (Figure 1 below) runs both IPv4 and IPv6 protocol stacks on a router in parallel, making it
similar to the multiprotocol network environments of the past, which often ran Internetwork Packet
Exchange (IPX), AppleTalk, IP, and other protocols concurrently. The technique of deploying IPv6
using dual-stack backbones allows IPv4 and IPv6 applications to coexist in a dual IP layer routing
backbone. The IPv4 communication uses the IPv4 protocol stack, and the IPv6 communication
uses the IPv6 stack.
As a transition strategy, dual stack is ideal for campus networks with a mixture of IPv4 and IPv6
applications.
Figure 1:Dual-Stack Example

Reference:
http://www.cisco.com/en/US/products/ps6553/products_white_paper0900aecd805c54d0.shtml