When should you turn on your headlights?

Answer: B — 1/2 hour after sunset and before sunrise

You should turn on your headlights 1/2 hour after sunset and before sunrise because this is when visibility may be reduced due to low light conditions. Turning on your headlights during these times helps you see the road clearly and helps other drivers see your vehicle. Option A, turning on headlights 1 hour after sunset, could be too late as visibility may already be significantly reduced. Option C, turning on headlights 1 hour before sunset, is unnecessary as visibility is still relatively good at that time. Option D, turning on headlights at noon, is not necessary as it is during daylight hours when visibility is usually good.