Dry chemical extinguishers may be used on what class of fires?

Correct Answer: Option D — A, B or C as marked on the extinguisher

Classification markings per 46 CFR specify unit capabilities. Multi-purpose dry chemical (ammonium phosphate) handles Classes A, B, and C, whereas regular types are limited to Classes B and C. Mariners must verify the rating stamped on the fire extinguisher label.