What type of signal is capable of displaying a Stop indication and is controlled by the Rail Traffic Controller?

The correct answer pertains to the nature of controlled signals within the railway system. Controlled signals are specifically designed to provide indications such as "Stop" and others, and they are directly monitored and operated by the Rail Traffic Controller. This means that the signals can change in response to the commands from the Rail Traffic Controller based on real-time situations on the railway network, thereby enhancing safety and operational efficiency.

Fixed signals, on the other hand, are pre-set and remain in place regardless of ongoing operations, making them less flexible than controlled signals. Manual signals rely on personnel to operate them, meaning they may not always provide immediate updates as circumstances change. Automated signals generally function without direct human intervention but are typically not tied to real-time commands from a controller. Therefore, the capabilities and operational oversight of controlled signals make them the most accurate representation of the requirement to display a Stop indication while being managed by a Rail Traffic Controller.