What information must be provided in a trackside warning detector message?

The correct answer focuses on the crucial elements necessary for safe and efficient train operations. In a trackside warning detector message, providing the train identification alongside the detector location allows dispatchers, engineers, and other relevant personnel to quickly determine which specific train is involved in a potential issue and where that train is located on the rail network.

This information is essential for effective communication and helps facilitate a prompt response to any alerts or warnings triggered by the detection systems. It ensures that all parties involved are on the same page regarding the situation at hand, thereby enhancing safety and operational efficiency on the railways.