The correct answer is D. FCC and RCC.
The FCC (Frequency Control Channel) is a control channel used to establish and maintain communication between a mobile phone and a base station. The RCC (Routing Control Channel) is a control channel used to route calls between mobile phones and the public switched telephone network (PSTN).
The FVC (Forward Voice Channel) is a voice channel used to carry voice traffic between a mobile phone and a base station. The RVC (Reverse Voice Channel) is a voice channel used to carry voice traffic between a base station and a mobile phone.
The FCC and RCC are responsible for initiating mobile calls because they are the channels that are used to establish communication between a mobile phone and a base station. The FVC and RVC are responsible for carrying voice traffic between a mobile phone and a base station, but they are not responsible for initiating calls.