If it is impractical to use the fill line to sound the fuel tank, then the tank should be fitted with __________. (Small Passenger Vessel Regulations)

Correct Answer: Option D — a separate sounding tube or an installed marine type fuel gauge

46 CFR 182.440 requires that if a fuel tank cannot be sounded via the fill line, it must be fitted with a separate sounding tube or an installed marine-type fuel gauge. This ensures the Master can accurately determine fuel levels, preventing fuel starvation or overfilling during bunkering operations.