What do you do if visibility is drastically reduced by fog?

Your answer is correct because when visibility is drastically reduced by fog, German traffic rules emphasize two key safety measures. First, you must adjust your speed to the current visibility conditions to ensure you can stop safely if an obstacle appears suddenly. Second, increasing the distance to the vehicle in front allows more reaction time and reduces the risk of a collision, as stopping distances increase in foggy conditions. The third option, driving close to the vehicle in front, is dangerous and prohibited because it reduces your reaction time and increases the risk of accidents. Always maintain a safe distance and adapt your speed appropriately in fog.