What should the condition of front exterior lights on a school bus be?

Answer: A — All are clean, no broken or missing lenses

The condition of the front exterior lights on a school bus is critical for safety and visibility. The ideal state is that all lights are clean, and there are no broken or missing lenses. This ensures that the lights function effectively to signal other drivers, improve visibility during low light conditions, and make the bus recognizable as a school vehicle. Having clean lights allows for maximum brightness and clarity, which is especially important for the safety of students getting on and off the bus. Any damage, such as broken or missing lenses, can significantly impair the bus's lighting capabilities and lead to dangerous situations on the road. This makes the correct answer the only viable option that meets safety standards and regulations for school buses.