The correct answer is: B. the center of gravity of the body and the center of buoyancy.
Metacentric height is the distance between the center of gravity of a ship and its metacenter. The metacenter is the point of intersection of the vertical line through the center of buoyancy and the line of action of the buoyant force.
The metacentric height is important because it determines the stability of a ship. A ship with a large metacentric height is more stable than a ship with a small metacentric height. This is because a ship with a large metacentric height will return to its original upright position more quickly after being disturbed.
The metacentric height can be increased by increasing the distance between the center of gravity and the center of buoyancy. This can be done by raising the center of gravity or by lowering the center of buoyancy.
The metacentric height can also be increased by increasing the draft of the ship. This is because the center of buoyancy will move lower in the water as the draft increases.
The metacentric height is a critical factor in the design of ships. It is important to ensure that the metacentric height is large enough to ensure the stability of the ship.