The correct answer is D) All of the above. The safe transportation and handling of liquefied gas requires: 1) A system of cargo tanks and piping that is free from leaks to prevent the release of flammable or hazardous gas. 2) Cargo tanks and piping that are located or protected to minimize the risk of physical damage, which could lead to leaks or breaches. 3) Cargo tanks and piping that are strong enough to withstand the high pressures associated with liquefied gas cargo. All three of these factors are critical safety concerns that must be addressed when transporting and handling liquefied gas to prevent accidents and ensure the safe operation of the vessel.