What should you do if you are driving in heavy fog?

Answer: B — Use low-beam headlights and reduce speed

When driving in heavy fog, using low-beam headlights is crucial because they illuminate the road without reflecting excessive light off the fog, which can create glare and reduce visibility further. Low-beam headlights provide a clearer view of the road and any obstacles, making it safer to navigate through such conditions. Additionally, reducing speed allows for better reaction time and enhances safety, as visibility can be significantly compromised in heavy fog. Maintaining a slower speed enables drivers to react appropriately to unexpected situations, such as other vehicles or road hazards that may suddenly appear. It is also important to adjust your driving behavior in such conditions to ensure not only your safety but also the safety of others on the road.