What would be the most effective agent to use to extinguish a fire in drums of flammable liquids stowed on the weather deck of a vessel?

Correct Answer: Option D — Foam

Foam provides a continuous floating blanket that suppresses flammable vapors and cools the fuel surface. On weather decks exposed to wind, gaseous agents like CO2 dissipate too rapidly to be effective, while water alone can spread burning liquid.