What does the total stopping distance consist of?

Answer: D — 3 parts: perception, reaction, braking

The total stopping distance refers to the distance a vehicle travels from the moment the driver perceives a hazard to the point where the vehicle comes to a complete stop. This distance is affected by three main factors perception of the hazard, reaction time of the driver, and the braking distance of the vehicle. Option D correctly lists all three components that make up the total stopping distance. Option A and B are incorrect because perception and reaction alone do not fully make up the total stopping distance. Option C is also incorrect because braking distance only accounts for a portion of the total stopping distance. Therefore, option D is the most accurate and complete answer.