The correct option is A True
Unlike a ship, a submarine can control its buoyancy, thus allowing it to sink and surface on demand. To dive, the submarine tanks are opened to allow air to exhaust, while the water is allowed to flow in until its overall density is greater than the surrounding water and the submarine begins to submerge. When the weight of the submarine has been balanced such that the overall density of it is equal to the water around it, it has neutral buoyancy. An object that has neutral buoyancy will neither sink nor rise. Neutral buoyancy helps submarine to float underwater without sinking.