What should you do if your windshield wipers are not effective during heavy fog?

Answer: B — Pull to a safe area until visibility returns

When faced with heavy fog and ineffective windshield wipers, pulling to a safe area until visibility improves is the most prudent action to take. Heavy fog significantly reduces visibility, making it extremely difficult to see the road and other vehicles. By pulling over to a safe location, you minimize the risk of an accident while waiting for conditions to improve. This approach ensures your safety as well as the safety of others on the road. Staying put until visibility returns allows you to make more informed decisions about when it is safe to drive again. In contrast, trying to increase your speed to get through fog can lead to dangerous situations, as you may not see obstacles or other vehicles in time to react. Aiming headlights at the fog is not effective since fog can reflect light, which may actually worsen visibility. Similarly, using the rear-view mirror to assist doesn't solve the fundamental problem of inadequate visibility ahead; it could distract you from the conditions you need to focus on while navigating through fog.