How should you maintain a safe following distance behind the vehicle ahead of you at speeds over 30 mph?

Answer: D — The four second rule

Maintaining a safe following distance is crucial to ensure safety while driving. When driving at speeds over 30 mph, the recommended minimum safe following distance is four seconds. This allows for enough time to react to any sudden changes or hazards on the road. Option A and B, the two and five second rule, are generally recommended for speeds below 30 mph. Option C, the seven second rule, is too long of a distance and can lead to other drivers cutting in front of you. Therefore, D, the four second rule, is the most appropriate option for maintaining a safe following distance at speeds over 30 mph.