Question 57

The Correct Answer is A **Why Option A is Correct:** A safe fuel system must be liquid- and vapor-tight (sealed) primarily for safety and environmental reasons. Gasoline is highly flammable and volatile. If the system is not sealed, liquid fuel can leak, creating a fire hazard, and gasoline vapors (which are even more easily ignited) can escape into the atmosphere or the engine bay. Being liquid- and vapor-tight prevents leaks, minimizes fire risk, and meets environmental regulations concerning the release of volatile organic compounds (VOCs). **Why the Other Options are Incorrect:** * **B) supply sufficient air to the intake manifold:** Supplying air is the primary function of the *air intake system* or *induction system*, not the fuel system itself. The fuel system’s role is to meter and deliver fuel. * **C) have proper air/gasoline fuel mixture ratio:** While achieving the proper fuel mixture (stoichiometric ratio) is crucial for efficient and clean engine operation, this is a matter of *performance and emission control*, not the fundamental definition of a *safe* fuel system. A leaky system is unsafe even if it momentarily achieves the correct mixture ratio. * **D) prevent engine overheating:** Preventing engine overheating is the function of the *cooling system* (radiator, water pump, thermostat), not the fuel system.