Router R1, a branch router, connects to the Internet using DSL. Some traffic flows through a GRE and IPsec tunnel, over the DSL connection, destined for an Enterprise network. Which of the following answers best describes the router's logic that tells the router, for a given packet, to apply GRE encapsulation to the packet?（）

A. When the packet received on the LAN interface is permitted by the ACL listed on the tunnel greacl command under the incoming interface
B. When routing the packet, matching a route whose outgoing interface is the GRE tunnel interface
C. When routing the packet, matching a route whose outgoing interface is the IPsec tunnel interface
D. When permitted by an ACL that was referenced in the associated crypto ma