Please help question in picture

C

Explanation:

The graph with the greatest slope is the one with the highest velocity.

For Graph 1, the slope is 25/30, which is 0.833 m/s.

For Graph 2, the slope is 50/60, which is also 0.833 m/s.

For Graph 3, the slope is 100/30, which is 3.33 m/s.

For Graph 4, the slope is 100/60, which is 1.67 m/s.

Graph 3 has the highest slope, so it is the one that represents the greatest velocity.