A tank vessel with an oil cargo capacity of 5000 barrels is required by regulations to have a fixed container, or enclosed deck area under or around each oil loading manifold and each oil transfer connection point. The capacity of these containment areas is based upon __________.

Correct Answer: Option A — inside transfer hose diameter or loading arm nominal pipe size diameter

33 CFR 155.780 mandates that containment capacity for oil loading manifolds must be sized based on the nominal diameter of the transfer hose or loading arm. This ensures the containment area can effectively capture potential spills during connection or disconnection, preventing environmental discharge as required by federal pollution prevention standards.