How should you react when driving in fog?

Answer: B — Use low beam headlights and reduce speed

When driving in fog, the proper response is to use low beam headlights and reduce speed. Low beam headlights are specifically designed to illuminate the roadway immediately in front of your vehicle without causing additional glare that can reflect off the fog and impair your visibility. Using high beam headlights in foggy conditions can actually make it harder to see, as the light reflects off the fog and creates a wall of brightness that can obscure your view. Reducing speed is crucial in fog because visibility is limited. Slowing down allows for better reaction time to any obstacles or changes in road conditions, which can be especially important when you cannot see far ahead. This combination of measures enhances safety for you and other road users in conditions where visibility is significantly compromised.