Final answer:
In bad weather, using low beam headlights is the best option for ensuring that your vehicle is visible to others while not impairing their vision with glare.
Step-by-step explanation:
When driving in bad weather, you should make your vehicle easier for others to see by using low beam headlights. High beam headlights can cause glare and make it more difficult for other drivers to see, particularly in fog, rain, or snow conditions. Turning off all lights or driving with only parking lights is not advisable as it decreases vehicle visibility. Using low beam headlights is the correct practice, as it enhances your car's visibility to other drivers without causing glare that can impair their vision.