On small passenger vessels, what type of devices are required at both the tank and engine connections of all internal combustion engine fuel lines?

Correct Answer: Option B — Shut-off valves

46 CFR 182.440 requires shut-off valves at both the fuel tank and the engine connection. These valves are critical for isolating the fuel supply in the event of a leak or fire, preventing the entire contents of the fuel line from feeding a potential hazard.