On board small passenger vessels, ducts for compartments which contain gasoline powered machinery or gasoline storage tanks __________.

Correct Answer: Option D — All of the above

46 CFR 182.460 mandates that ventilation ducts for gasoline-powered machinery spaces must be of rigid, permanent construction, lead directly to the open atmosphere, and be properly supported. These requirements prevent the accumulation of explosive gasoline vapors, ensuring the vessel's structural and fire safety integrity.