Answer:
A line graph
Step-by-step explanation:
A line graph would be the best type of graph to show changes over time. A line graph constitutes of a y-axis and an X- axis. The presence of the axis will make is easier to look at the height changes which occur over time. The y-axis of such a graph could show the height, the X axis of such a graph could show the time. Hence, a line graph could be the best one to represent such a change.