The damping coefficient of a uniform rigid bar suspended by a spring-damper arrangement

Question

A uniform rigid slender bar of mass 10 kg. is hinged at the left end is suspended with the help of spring and damper arrangement as shown in the figure where K = 2kN/m, C = 500Ns/m and the stiffness of the torsion spring K_q is 1 kN/m/rad. Ignore the hinge dimensions.         

2)  The damping coefficient in the vibration equation is given by

(a) 500 Nms/rad                                                  (b) 500 N(m/s)

(c) 80 Nms/rad                                                    (d) 80N/(m/s)