A. interface atm 5\/1 atm pvc 1 0 101 aal5snap encapsulation ppp ppp authentication chap ip unnumbered loopback 1
B. interface atm 5\/1 atm pvc 1 0 101 aal5snap encapsulation pppoe interface pppoe 5\/1 encapsulation ppp ppp authentication chap ip unnumbered loopback 1
C. interface atm 5\/1 atm pvc 1 0 101 aal5snap encapsulation pppoe interface atm 5\/1 encap ppp ppp authentication chap ip unnumbered loopback 1
D. interface atm 5\/1 atm pvc 1 0 101 aal5snap encapsulation pppoe ppp authentication chap ip unnumbered loopback 1
参考答案：C
