When is a motorist required to turn on their headlights?

Answer: C — During twilight hours or low visibility

Turning on headlights during twilight hours or in conditions of low visibility is essential for ensuring safety on the road. Headlights improve visibility for drivers, allowing them to see the road more clearly and spot obstacles or other vehicles in dim lighting. Moreover, headlights make the vehicle more visible to others, reducing the risk of accidents, particularly during dawn and dusk when lighting conditions can change rapidly. Additionally, while there are circumstances where headlights are specifically required, such as in foggy conditions or on highways, the requirement to use headlights during twilight hours or low visibility encompasses broader scenarios. This requirement is meant to enhance safety and promote road visibility under various driving conditions, making it a critical rule for all motorists.