Before leaving the location of a main track switch, what must the employee handling the switch transmit over the radio?

The best choice for what the employee handling the switch must transmit over the radio is the details of the switch's status and position. This communication is crucial for ensuring the safety and efficiency of train operations. By relaying the specific status, including whether the switch is aligned for the main line or diverging route, the dispatcher and other crew members can be fully informed about the current track conditions. This information helps prevent misunderstandings that could lead to dangerous situations, such as a train entering a track that is not set for its intended route.

Transmitting just the switch's normal position would not provide complete information about the current status of the switch. Similarly, simply stating the number of trains scheduled or the name of the control operator does not address the critical safety need to communicate the particular state of the switch itself. Clear communication regarding the switch’s details ensures all personnel are aware of the operational situation, thus enhancing safety protocols on the railway.