The device used for preventing the passage of flames into enclosed spaces is called a __________.

Correct Answer: Option A — flame arrester

Flame arresters utilize a matrix of fine mesh or crimped metal ribbons to dissipate heat from a flame front, quenching it before it can propagate into a protected space. This mechanism is critical in fuel tank vents and engine air intakes to prevent ignition of flammable vapors per 46 CFR.