Final answer:
When the lights on your car are dimmed at night, you should slow down to allow your eyes to adjust to the lower visibility and to ensure that you can react adequately to any potential hazards on the road.
Step-by-step explanation:
When you dim your lights at night, the correct action regarding speed is A. Slow down. This is because dimming your lights reduces your visibility, and your eyes need time to adjust to the lower light levels, a process called "dark adaptation." Similar to when you enter a dark movie theater and can't see anything at first but gradually can see clearer, dimming your car lights requires giving your eyes time to adjust. It's also crucial to consider that at reduced light levels, your ability to perceive obstacles and gauge distances is significantly decreased, so reducing speed is a safety measure to compensate for the reduced reaction time.
Safety becomes a key concern when the visibility is compromised, hence slowing down helps mitigate potential hazards on the road. If you continue to drive at the same speed with diminished sight, you increase the risk of not seeing an obstacle or hazard in time to react appropriately. Therefore, particularly at night when you dim your lights, it's important to adjust your driving speed accordingly.