Refer to the exhibit. Which statement describes DLCI 17?()<br /> <img src="https://nimg.ppkao.com/2018-07/yiyu/2018072315024157932.jpg?sign=a46e554a3f70ce4582b4e2dace1ada0c&t=62d4e911" />
A、DLCI 17 describes the ISDN circuit between R2 and R3.
B、DLCI 17 describes a PVC on R2. It cannot be used on R3 or R1.
C、DLCI 17 is the Layer 2 address used by R2 to describe a PVC to R3.
D、DLCI 17 describes the dial-up circuit from R2 and R3 to the service provider.