Subtracting the height of the center of gravity corrected for longitudinal free surface effects from the height of the longitudinal metacenter of a MODU yields __________.

Correct Answer: Option A — GML

Longitudinal metacentric height ($G_M_L$) is fundamentally defined as the vertical distance between the longitudinal center of gravity (corrected for longitudinal free surface effects) and the longitudinal metacenter ($K_M_L$), per standard stability principles.