Which force, together with the weight of the submarine (the gravitational force of the Earth on the submarine), makes a pair according to Newton's third law of motion?
the upward buoyant force (upthrust) exerted on the submarine by the surrounding seawater
the downward force exerted by the submarine's hull on the surrounding seawater
the gravitational force exerted by the submarine on the Earth
the downward water pressure force acting on the upper surface of the submarine
