A wheel of moment of inertia 5 × 10⁻³ kgm² is making 20 rev/s. The torque required to stop it in 10 s is-

a. 2 × 10⁻² Nm
b. 2 × 10² Nm
c. 4 × 10⁻² Nm
d. 4 × 10² Nm