A car driver who is moving in a straight line at constant speed notices a hazard in the road ahead at time $= 0$. The speed-time graph shows the way the car’s speed varies from time $= 0$. Three students give their ideas about what area $X$ and area $Y$ mean. student 1: Area $X$ shows the thinking distance. student 2: Area $Y$ shows the stopping distance. student 3: Area $X$ + area $Y$ shows the stopping distance. Which students are correct?
- A1 and 2
- B1 and 3
- C1 only
- D2 only