What should a driver do when driving in foggy conditions?

Answer: C — Reduce speed and use low beam headlights

When driving in foggy conditions, it is crucial to reduce speed and use low beam headlights. Fog significantly reduces visibility, making it difficult to see other vehicles and obstacles on the road. By slowing down, a driver can react more effectively to sudden changes in the driving environment. Using low beam headlights is also important because high beams can reflect off the fog, causing a glare that worsens visibility instead of improving it. Low beams help illuminate the road immediately in front of the vehicle without causing excessive reflection. This combination of reduced speed and appropriate lighting enhances safety in challenging weather conditions like fog. Choosing not to adjust speed or using high beams would not mitigate the risks associated with decreased visibility. Also, switching off the headlights completely would leave a driver unable to see the road or be seen by other vehicles, which could lead to dangerous situations. Thus, reducing speed and using low beam headlights are the correct and safest practices in foggy conditions.