U.S. regulations require cargo pump rooms, on tank vessels handling grades A, B, or C liquid cargo, shall be equipped with power ventilation of the exhaust type. in what amount of time should the ventilation effect a complete change of air?

Correct Answer: Option C — not more than 3 minutes

Per 46 CFR 32.60-20, pump rooms on tank vessels handling Grades A, B, or C flammable liquids require mechanical exhaust ventilation capable of completely changing the space's air volume within a maximum of 3 minutes to prevent hazardous vapor accumulations.