When are you required to use your headlights?

Headlights are essential for safety and visibility on the road. The correct answer emphasizes using headlights when visibility is poor and during nighttime driving because these conditions significantly reduce a driver's ability to see and be seen by others. Poor visibility can arise not only at night but also during adverse weather situations like fog, heavy rain, or snow.

Using headlights in these situations helps ensure that other drivers can see your vehicle, and it allows you to see the road and any obstacles more clearly. While headlights are crucial for nighttime driving, their use during poor visibility conditions is equally important to enhance safety for all road users.

The other options suggest more limited circumstances in which headlights are used, which does not enhance overall driving safety as effectively as the broader criteria presented in the correct answer.