A、When a router receives a failure response, it stops querying authentication methods.

B、When a router receives an error response, it stops querying authentication methods.

C、If the router receives a failure response from an authentication method, it queries the next method.

D、The router does not differentiate between failure and error responses; the authentication process is always interrupted.

E、If it receives no response from the authentication method, a router will determine the error condition on its own; the router also has the option to proceed to the next method in a list if configured accordingly.