The size of the fire hydrant hose connections must be either 1 1/2 inches or __________.

Correct Answer: Option B — 2 1/2 inches

46 CFR regulations standardize fire hose connections to ensure compatibility with shore-side firefighting equipment and shipboard hoses. The required sizes for fire hydrants and hose couplings are 1 1/2 inches for smaller applications and 2 1/2 inches for standard main deck and engine room fire stations.