Explain the function of "automatic train control" (ATC).

Automatic train control (ATC) is a system designed to enhance the safety and efficiency of train operations. Its primary function is to monitor train speeds and ensure compliance with signal indications, which plays a crucial role in accident prevention. ATC systems are integrated into the train's control systems, providing real-time data and feedback to the operator. If a train exceeds a predetermined speed or fails to respond to signals appropriately, the ATC can automatically intervene, such as by applying brakes to slow the train down or bring it to a stop.

This capability minimizes the risk of human error by providing an additional layer of oversight, contributing significantly to overall railway safety. Other options, while related to train operations, do not accurately capture the primary function of ATC; for example, they deal with passenger information, loading protocols, or station management rather than the direct monitoring and enforcement of operational safety.