Liquefied flammable gas is defined as any flammable gas having a Reid vapor pressure exceeding how many pounds?

Correct Answer: Option C — 40

Title 46 CFR 30.10-39 defines a liquefied flammable gas (LFG) as any flammable gas having a Reid vapor pressure exceeding 40 pounds per square inch at 100°F. This high vapor pressure necessitates specialized pressurized or refrigerated containment systems during transport.