Which of the following statements are correct?
1. Centre of mass of a body always coincides wiith the centre of gravity of the body.
2. Centre of gravity of a body is the point where total gravitational torque on the body is zero.
3. A couple on a body produces both translational and rotational motion in a body.
4. Mechanical advantage greater than one means that a small effort can be used to lift a large load.
A) (1) and (2)
B) (2) and (3)
C) (3) and (4)
D) (2) and (4)