Router R1, a branch router, connects to the Internet using DSL. The engineer plans to use a configuration with a dialer interface. The answers list a feature and interface on which the feature could be configured. Which combinations accurately describe the interface under which a feature will be configured?（）

A. PPP on the ATM interface
B. VPI/VCI on the dialer interface
C. IP address on the ATM interface
D. CHAP on the dialer interface