When should headlights be used?

Headlights are essential for ensuring visibility and safety while driving, particularly in low-light or challenging conditions. Using headlights at night is crucial, as they illuminate the road ahead and make the vehicle more visible to other drivers, helping to prevent accidents. Additionally, they should be used during bad weather conditions such as rain, fog, or snow, when visibility is significantly reduced. This use of headlights improves the driver's ability to see the road and enhances the visibility of the vehicle to others, which is key to maintaining safety on the road.

The other options suggest limited or inappropriate usage of headlights. For instance, only using headlights in well-lit areas may lead to dangerous situations in darker conditions where visibility is compromised. Limiting their use to daytime only ignores the necessity of headlights during low-visibility situations, while only using them when parking does not align with safe driving practices that require clear visibility while moving.