Which of the following is NOT an example of zero work ?

The work done when a horse pulls a cart on a level road

1. In circular motion, the net displacement is zero. So the work done is zero too. Thus, \(W = zero\)
2. The force is in forward direction and so is the displacement. Thus, \(W \neq zero\)
3. The work is done against the gravitational force which acts downwards. The displacement is forward in direction. Thus, \(W = zero\)
4. The force is in action but there is NO displacement. Thus, \(W = zero\)