Final answer:
When driving on icy roads, it is important to maintain a safe distance from the vehicle you are following. A distance of at least 12 car lengths, or approximately 48 meters, is recommended. So, the correct answer is option d.
Step-by-step explanation:
When driving on icy roads, it is recommended to leave a distance equivalent to at least 12 car lengths between your vehicle and the one you are following, regardless of your speed. This allows for a safe braking distance and reduces the risk of collision. For example, if each car length is approximately 4 meters, then you should be at least 48 meters away from the vehicle in front of you. So, the correct answer is option d.