In the uninspected vessel regulations what does the "B" on a "B-II" fire extinguisher refer to?

Correct Answer: Option A — Class of fire that the extinguisher should be used on

Per 46 CFR regulations, the letter prefix in a fire extinguisher classification (such as the 'B' in 'B-II') designates the class of fire the unit is designed to combat. Class B specifically refers to fires involving flammable and combustible liquids, greases, and petroleum.