What size hoses are used within the house? On the weather decks?

Correct Answer: Option C — 1.5", 2.5"

Standard maritime fire main configurations utilize 1.5-inch hoses for interior accommodation spaces to ensure maneuverability in confined areas, while 2.5-inch hoses are required on weather decks to provide the higher volume and pressure necessary for effective firefighting in open, high-risk environments, consistent with 46 CFR requirements for vessel fire protection.