As a bug drops vertically from a point meters above a bush to a leaf on the bush, its gravitational potential energy Ug(y) 1. remains constant. 2. increases by the amount of work you would have to do against gravity to carry the bug from the leaf to its original position. 3. increases by the amount of work gravity does on the bug as it drops. 4. decreases by the magnitude of the amount of work gravity does on the bug as it drops.