The correct answer is: B. when the metacentre is above the centre of gravity.
A floating body is said to be in a state of stable equilibrium when the metacentre is above the centre of gravity. This means that if the body is disturbed, it will tend to return to its original position.
The metacentre is a point located above the centre of buoyancy. The centre of buoyancy is the point where the upward force of buoyancy acts on the body. The metacentre is located above the centre of buoyancy because of the shape of the body. The shape of the body causes the water to exert a force on the body that is not directly below the centre of gravity. This force causes the metacentre to be located above the centre of gravity.
If the metacentre is below the centre of gravity, the body is said to be in a state of unstable equilibrium. This means that if the body is disturbed, it will tend to move further away from its original position.
The metacentric height is the distance between the metacentre and the centre of gravity. The metacentric height is important because it determines whether the body is in a state of stable or unstable equilibrium. If the metacentric height is zero, the body is in a state of neutral equilibrium. This means that the body will neither return to its original position nor move further away from its original position if it is disturbed.
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