The correct option is A Gravitational Force
The ball is falling downwards due to the gravitational force. Gravitational force is a non-contact force which exists between any two objects because of their masses. It is always attractive in nature. It is because the earth pulls all objects towards its centre. The pull exerted by the earth on the objects is called the force of gravity. When we throw an object vertically upward the force of gravity of earth starts acting on it. Firstly, it slows down the object and finally pulls down.