Answer:
Part A: [0,2], Part B: [2, 4], Part C: [8,10], Part D: 0 ft
Explanation:
Part A: The time between 0 seconds to 2 seconds is the time when it's increasing. There is no other time like that.
Part B: The graph shows a straight line so therefore it is staying the same.
Part C: The graph shows a sharp decline.
Part D: Starting from the 10th second, the balloon already hit to ground so it would only make sense for it to stay there...