When must you use headlights in Washington?

Answer: C — Between sunset and sunrise, and during poor visibility

Headlights are required in Washington state between sunset and sunrise because visibility is significantly reduced during these hours. Additionally, headlights must be used during poor visibility conditions, such as rain, fog, or heavy snow. This regulation is in place to ensure that drivers can see the road clearly and be seen by others, reducing the risk of accidents. While it may seem reasonable to think that headlights are only needed at night or during specific weather conditions, the law encompasses a broader range of scenarios. For instance, even during daytime hours, if rain or fog reduces visibility, the use of headlights is necessary for safety. Therefore, the correct answer indicates that both the time of day and certain weather conditions dictate the need for headlights.