Typical ADSL broadband Internet access requires a username and password to be entered on end-user PC connected to the ADSL modem in order for the end user to gain access to the Internet.if a Cisco ADSL router is used instead of an ADSL modem,what functionality is required on the Cisco ADSL router so the end-user connected to the Cisco ADSL router can access the Internet without entering a username and password?

A.
PPPoA

B.
Route Bridge Encapsulation(RBE)

C.
PPPoE client

D.
Integrated Routing and Bridging(IRB)

E.
AAA