On a bulk chemical carrier, water should NOT be used as an extinguishing agent to fight a fire if the water may come into contact with the chemical called __________.

Correct Answer: Option B — oleum

Oleum (fuming sulfuric acid) reacts violently and exothermically with water, causing severe splattering, dangerous acid mist generation, and rapid container pressurization. Bulk chemical carriage regulations strictly prohibit water use on water-reactive cargoes.