Speed can be shown on a graph of distance versus time. The graph below shows the distance Mr. Martin traveled on his skateboard and the amount of time it took him to travel that distance.

What may have happened in the time period between 5 and 8 seconds?
A. His speed increased
B. He is jogging at a constant speed
C. He stopped moving
D. His speed increased

Based on the information given, it is not possible to determine what may have happened in the time period between 5 and 8 seconds. The graph does not provide any information about what Mr. Martin did during that time period.