When must headlights be used?

Answer: C — From half an hour after sunset until half an hour before sunrise, and whenever visibility is less than 500 feet

Headlights are essential for visibility and safety while driving. They must be used from half an hour after sunset until half an hour before sunrise, which ensures that drivers are visible to others during low-light conditions typical of twilight and nighttime. Additionally, headlights are required whenever visibility drops below 500 feet, which can occur in various situations such as fog, heavy rain, or snow. This regulation helps improve safety by providing better visibility for both the driver and other road users during adverse weather conditions or at times of reduced natural light. In contrast, the other options do not encompass all scenarios where headlights are necessary, such as times when visibility is poor due to weather or after sunset. Limiting headlight use to nighttime hours only or specific weather conditions does not account for the full range of situations in which they should be utilized.