Which of the choices below does NOT indicate a communication system component?

A fuel pump is primarily a mechanical component utilized within an aircraft's fuel system to move and manage fuel from the tanks to the engine. Unlike the other options, which are directly related to facilitating communication, a fuel pump does not play any role in data transmission or reception.

On the other hand, a satellite link, microphone, and transmitter are essential components of a communication system. The satellite link enables long-distance communication by relaying signals, the microphone captures audio input for transmission, and the transmitter converts information into a format suitable for sending via communication channels. Thus, the fuel pump stands out as it operates independently of the communication functions present in the other components.