What is one of the key factors to ensure safety while riding a motorcycle at night?

Answer: B — Keeping the motorcycle's lights clean and functional

One of the key factors to ensure safety while riding a motorcycle at night is keeping the motorcycle's lights clean and functional. Proper lighting is crucial because visibility decreases significantly at night. Motorcycle headlights illuminate the road ahead, while taillights and brake lights alert other drivers to your presence and intentions. If the lights are dirty or not functioning correctly, their effectiveness can be drastically reduced, leading to potentially hazardous situations. This helps both the rider see clearly and be seen by others, substantially lowering the risk of accidents. While riding in well-lit areas and adjusting speed are important safety considerations, they are not as directly impactful as ensuring that all lights are operational and clean. Similarly, wearing goggles can protect against wind and debris but does not address the primary concern of visibility that lighting provides at night.