Which of the following stations transmits signals over the air from a remote receive site to a repeater for retransmission?

The best choice for this question is an auxiliary station. An auxiliary station is designed to support the primary functions of amateur radio by facilitating communication between different locations, particularly in situations where signals need to be transmitted over longer distances or when a direct line of sight is not available. In the context of this question, an auxiliary station can receive signals from a remote site and then transfer those signals to a repeater, which amplifies and retransmits them so they can reach users who are further away.

This function is crucial in repeater systems, where the goal is to enhance communication range. Auxiliary stations can manage various tasks, including connecting multiple radios or relays and ensuring reliable service in emergency communication situations. Thus, this reinforces the role of auxiliary stations in the overall network of amateur radio communication.