Which type of driving condition necessitates the use of headlights?

The necessity of using headlights in foggy or rainy weather stems from the fact that such conditions significantly reduce visibility. Headlights help illuminate the road and increase your visibility to other drivers, which is crucial for safety. In fog, headlights can often create glare, so using low beams is recommended to minimize this issue. Similarly, in rain, headlights enable not just the driver to see better, but also make the vehicle more visible to others on the road, potentially preventing accidents.

While headlights are commonly used at night to ensure visibility, they aren't limited to that time frame; they are also crucial in adverse weather conditions like fog and rain, where visibility can be compromised. The other options suggest limitations on when headlights should be used, which do not account for important driving circumstances that require enhanced visibility.