B > A = C = D

For A and C, there is no change in speed, hence no change in kinetic

energy and no work done. For D, the speed changes, but there is no change in kinetic energy (final K = initial K), so no work is done (negative

work from 15 s to 17.5 s is canceled by positive work from 17.5 s to 20 s). For B, the speed increases, as does the kinetic energy, so positive work is

done.