The inertia of the flywheel

Question

The speed of an engine varies from 210 rad/s to 190 rad/s. During cycle the change in kinetic energy is found to be 400 Nm. The inertia of the flywheel in kgm² is                                                                                        

      (a) 0.10                                                               (b) 0.20

      (c) 0.30                                                               (d) 0.40