Which light turns on when a driver applies the brakes?

When a driver applies the brakes, the high mount lamp, also known as the third brake light, activates to alert other drivers that the vehicle is slowing down or stopping. This light is particularly important as it is positioned higher than the standard brake lights, making it more visible to drivers behind the vehicle. Its purpose is to enhance safety by providing an additional warning signal and ensuring that the driver’s intention to stop is clearly communicated.

The other options do not serve this purpose. The turn signal indicates the direction in which a vehicle intends to turn or change lanes, while the park lamp is used for visibility when the vehicle is parked. The fog light is designed to improve visibility in foggy conditions and does not activate when the brakes are applied.