In what position should switches connecting any track, except a main track, to a siding be?

The correct choice relates to the operational safety and efficiency of rail operations when managing track situations involving sidings and switches. When switches connecting any track to a siding are lined and locked or secured for movement on the siding, it ensures that trains can safely enter and exit the siding without the risk of unintended movements that could occur if the switch were positioned incorrectly.

This setup is crucial because it clearly indicates the intended path for trains, preventing accidents that could arise from switches that are not correctly positioned. A lined and locked switch confirms that the track configuration is stable and safe, thus enhancing overall operational reliability. In practice, this means that crew members can confidently rely on the switch to guide trains into the appropriate siding, ensuring smooth operations.

Other options do not provide the level of safety and clarity needed in rail operations. For instance, switches lined for main track movement would misdirect trains and create significant risks. Similarly, switches that are free to move in any direction lack the necessary control, and switches in a reverse position for inspection might not facilitate safe train movements at all. The critical nature of maintaining safety through proper switch positioning reinforces why the selected answer is the most appropriate in this context.