When should you use your parking lights?

Answer: B — When visibility is impaired due to snow or heavy rain

You should turn on your parking lights when visibility is impaired due to snow or heavy rain. This will help other drivers see your vehicle in poor weather conditions. Depending on where you are, turning on your parking lights during daylight hours on highways (option C) may be illegal. Additionally, parking lights should not be used during foggy weather (option A) as they do not provide enough light to see through the fog. Similarly, turning them on whenever you are outside a city (option D) may not be necessary as it may not be in line with local laws or regulations.