When are drivers required to switch on their headlights?

Answer: D — All of the above

Drivers are required to switch on their headlights in various situations to ensure safety and visibility on the road. At dusk and dawn, the natural light can diminish, making it harder to see other vehicles and pedestrians, which is why headlights are essential during these times. Additionally, when weather conditions require it—such as during rain, snow, or heavy cloud cover—headlights help improve visibility and allow other road users to see the vehicle more clearly. In foggy conditions, headlights are crucial because they help in cutting through the reduced visibility that fog creates, ensuring that drivers are seen and can see the road ahead. Therefore, the requirement to use headlights encompasses all these scenarios, contributing to safer driving practices in varying conditions.