Question 5043 Deck General

The correct answer is C) displacement volume of the MODU. The free surface effect is the tendency of a partially filled liquid tank to shift the center of gravity of a vessel, which can reduce the vessel's stability. The displacement volume of the MODU (Mobile Offshore Drilling Unit) is directly related to the free surface effect - as the displacement volume increases, the free surface effect decreases. This is because the larger the overall displacement, the less significant the effect of the partially filled tank becomes. The other options are incorrect because they do not directly relate to the free surface effect. The density of the liquid (A) and the size of the surface area in the tank (D) can influence the free surface effect, but they are not the primary factor. The placement of the tank above the keel (B) may affect stability, but it does not directly impact the free surface effect.