If a ship is already loaded down to her marks, what can be done to increase GM?

Correct Answer: Option D — Both A and B

Metacentric height (GM) is improved by lowering the vertical center of gravity (KG). Filling slack tanks eliminates the free surface effect, which reduces virtual rise in KG, while transferring ballast to lower tanks physically lowers the center of gravity, thereby increasing the vessel's initial transverse stability as required by 46 CFR.