When should you increase your following distance?

Answer: C — In heavy traffic

You should increase your following distance in heavy traffic because it allows you more time to react to sudden stops or movements from the vehicles around you. In heavy traffic, there is an increased likelihood of unexpected changes in speed, so maintaining a greater following distance helps to provide you with a buffer zone for safe braking and maneuvering. This extra space can be crucial in preventing rear-end collisions and giving you more time to assess and respond to potential hazards on the road.