Which headlights should be used in rain or fog?

Answer: B — Low beam lights

When visibility is reduced by rain or fog, you want to illuminate the road without creating glare that bounces back at you. Low beam headlights do exactly that: they shine downward onto the road and the sides, helping you see lane markings and potential hazards without sending light straight into the moisture that can reflect it back. High beams, in contrast, shoot light farther ahead and reflect off rain or fog, creating glare that makes it harder to see. Fog lights can help in dense fog because they’re aimed low to illuminate near the ground, but they’re not a substitute for low beams in rain. Hazard lights are for emergencies or to warn others of a breakdown and don’t provide adequate road illumination for normal driving.