'One D channel operating at 16 Kbps' and 'two B channels operating at 64 Kbps each' describe the channels and data transfer rates used for ISDN BRI. Therefore, options B and C hold correct answers.
The full form of ISDN BRI is 'Integrated Services Digital Network Basic Rate Interface'. ISDN BRI is a configuration setting that delivers one D channel (Data Channel) at 16 Kbps and two B channels (Bearer Channels) at 64 Kbps each over an ordinary telephone line. The D channel is used for any combination of control/signaling, data, and X.25 packet networking. Whereas, the B channel is used for voice or user data.
SDN BRI is mostly used by smaller enterprises for voice-grade telephone services.
You can leran more about ISDN BRI at
https://brainly.com/question/24222349
#SPJ4