A flashing red light from the light gun instructs you to do what?

A flashing red light from the light gun indicates that an aircraft or vehicle must clear the taxiway or runway immediately. This signal is crucial for maintaining safety at airports, as it communicates an urgent need for all personnel and vehicles to vacate the area to avoid potential hazards or collisions. The flashing red light is a clear directive aimed at ensuring that the path is clear for aircraft operations. Understanding this signal is essential for anyone involved in airfield driving, as it emphasizes the importance of responding quickly to avoid dangerous situations.

In contrast, the other options serve different contexts; returning to the starting point may be necessary under certain conditions, proceeding to cross is relevant when given other types of signals, and exercising extreme caution does not address the immediate need for clearance that a flashing red light conveys.