Which of the following is the best advice when driving in foggy conditions?

Answer: A — Keep your eyes on the road ahead of you

The best advice when driving in foggy conditions is to keep your eyes on the road ahead of you. This is because using your high beams (option B) can actually make it more difficult to see, as the light will reflect off the fog and create a bright glare. Using your parking lights (option C) is also not recommended as they are not bright enough to provide adequate visibility. It is also important to not follow the tail lights of the car in front of you (option D) as they may be driving too fast or erratically in the fog, and you could end up in an accident. Therefore, the best course of action is to maintain focus on the road ahead and drive cautiously at a slow and safe speed.