A bus is moving with a speed of 10ms ⁻1 on a straight road. A scooterist wishes to overtake the bus in 100 s. If the bus is at a distance of 1 km from the scooteritst with what speed should the scooterist chase the bus?

A. 40ms ⁻1
B. 25ms ⁻1
C. 10ms ⁻1
D. 20ms ⁻1