which scenario could not be described by the following graph?

a. the altitude of a hiker who climbs up a mountain at a constant rate and then rests at the top of the mountain
b. the speed of a vehicle that accelerates at a constant rate and then reaches and maintains a constant cruising speed
c. the distance that a man is from home if he walks away at a constant rate and then stops for a period of time
d. the total distance a vehicle travels as it goes up a hill and then maintains a constant rate of speed at the top