How is traffic directed to a 6RD tunnel interface from the native IPv6 Internet?

How is traffic directed to a 6RD tunnel interface from the native IPv6 Internet?
A . Traffic is routed to the 6RD gateway of the ISP and encapsulated over IPv4 to the tunnel interface
B . Traffic is sent encapsulated in IPv4 from the native IPv6 host directly to the tunnel interface
C . Traffic is routed to the nearest public relay and encapsulated over IPv4 to the tunnel interface
D . Traffic is routed to the nearest public gateway and encapsulated over IPv4 to the tunnel interface

Answer: D