Which of the following statements are correct? [2017] (A) Centre of mass of a body always coincides with the centre of gravity of the body (B) Centre of mass of a body is the point at which the total gravitational torque on the body is zero (C) A couple on a body produce both translational and rotation motion in a body (D) Mechanical advantage greater than one means that small effort can be used to lift a large load (a) (A) and (B) (b) (B) and (C) (c) (C) and (D) (d) (B) and (D)