Which one of the following is NOT part of the fuel system?

The exhaust manifold is not part of the fuel system; instead, it is part of the exhaust system, which is responsible for directing exhaust gases away from the engine. The fuel system primarily deals with components that manage the intake, delivery, and utilization of fuel within the engine.

The intake manifold plays a crucial role in directing the air-fuel mixture into the engine cylinders, while the air cleaner filters the air entering the system to ensure proper combustion. Fuel lines are essential as they transport fuel from the tank to the engine. Understanding the distinctions among these components helps clarify their specific functions within the vehicle's systems and reinforces knowledge of engine mechanics.