Which of the following situations is an example of an unbalanced force acting on an object?

A tug-of-war ends in a tie with equal pulls on both sides of the rope.

A book rests on a table with gravity downward and the normal force upward of equal magnitude.

A skydiver falls at terminal velocity with air resistance equal in magnitude to weight.

A car accelerates forward because the forward static friction force from the road is greater than the backward resistive forces.