What should you do if you see a flashing blue or green light on a vehicle?
Answer: A — Yield the right-of-way to that vehicle.
If you see a flashing blue or green light on a vehicle, it typically indicates that it is an emergency or authorized vehicle such as a police car, ambulance, or fire truck. Yielding the right-of-way in this situation is crucial for the safety of both you and the emergency vehicle. Options B and C are incorrect because they suggest maintaining or increasing your speed, which can put both you and the emergency vehicle in danger. Option D is also incorrect as ignoring the light and continuing to drive can impede the emergency vehicle's progress and potentially lead to a dangerous situation.