System Of Particles And Rotational Motion Ques 53

53. A solid homogeneous sphere of mass $M$ and radius $R$ is moving on a rough horizontal surface, partly rolling and partly sliding. During this kind of motion of the sphere

[1988]

(a) total mechanical energy is conserved

(b) the angular momentum of the sphere about the point of contact with the plane is conserved

(c) only the rotational kinetic energy about the centre of mass is conserved in the absence of external torques

(d) angular momentum about the centre of mass is conserved.