Tyler throws a water balloon into the air from the top of a building, and it lands on the ground. The graph below models the height of the water balloon throughout its flight. Select the most appropriate unit to measure the amount of time that the water balloon is in the air. milliseconds minutes hours seconds

I can't exactly answer this question without the aid of the graph which was indicated in the problem above. However, I can answer this question based on context. For very tall buildings like the Empire State Building, the height is around 400 m. For such a long distance, the most appropriate unit for time would be minutes. You have to choose a unit that can be quantified in as few numbers as reasonable to be put on the graph as labels.