According to the diagram, a PPPoE session is initiated by the user from the PC using the username johndoe@isp1.com. This PPPoE session ultimately terminates on the ISP router, using domain based tunneling on 6400. What is the correct sequence of events which occur during user authentication?

A.
The 6400 will query the PC to get the domain name. The 6400 will issue a PPP authentication challenge to which the PC will respond using the username johndoe@isp1.com. Once the tunnel is established, the ISP router will issue a challenge to the user and will authenticate the response.

B.
The 6400 will issue a PPP authentication challenge to which the PC will respond using the username johndoe@isp1.com. The 6400 will authenticate the user. It will also use the domain name to find out the tunnel endpoint. The tunnel is established and user traffic will now be allowed to flow without any further authentication.

C.
The 6400 will issue a PPP authentication challenge to which the PC will respond using the username johndoe@isp1.com. The 6400 will use the domain name isp1.com to find out the tunnel endpoint. It will forward the authentication information to the ISP router which will authenticate the user.

D.
The 6400 will use the PVC number to decide the tunnel endpoint. Once the tunnel is established, the ISP router will issue a challenge to the user and will authenticate the response.

E.
None of the above