A recreational vessel 30 feet in length with no fixed fire extinguishing system in the machinery space must carry a minimum of ______ portable fire extinguisher(s).

Why A is correct

Per Table 1 to 33 CFR §175.320(a)(1), a vessel 26 feet or more but less than 40 feet with no fixed system in the machinery space requires a minimum of two 5-B portable fire extinguishers. One 5-B applies to vessels under 26 feet; three 5-B applies to the 40–65-foot range.