If the cause of a sudden severe list or trim is negative initial stability, counterflooding into empty tanks may __________.

Correct Answer: Option C — cause the unit to flop to a greater angle

Negative initial stability means the metacentric height (GM) is negative, placing the center of gravity above the metacenter. Introducing ballast into empty slack tanks lowers the effective center of gravity further off-center or adds free surface effect, causing the vessel to flop to a greater angle.