Yes, roll a ball up a slope. It will have a constant acceleration due to the slope. The velocity is not constant because the direction is changing. Carol is correct. In all the cases the ball s speed increases.
Acceleration is larger for steeper slopes.
Thus the first picture has a constant acceleration. The middle picture has a larger downward acceleration at first, which then decreases. The last picture has an increasing downwards acceleration. Thus the middle picture has a decreasing downward acceleration. The middle ball reaches the bottom first because it speeds up the fastest so it gets ahead of the other balls.