The part of an engine that supplies the fuel/air mixture to the cylinders is an?

The intake manifold is a critical component of an engine, as it is responsible for distributing the fuel and air mixture to the engine's cylinders. This mixture is essential for the combustion process that powers the engine.

When the engine operates, air enters the intake manifold through the throttle body, where it mixes with the fuel. The design and functionality of the intake manifold are crucial for optimizing engine performance and efficiency, as it ensures an even distribution of the fuel/air mixture to each cylinder for effective combustion.

While other components mentioned, such as the intake port and intake valve, play important roles in the engine's operation, they do not encompass the entirety of the process of supplying the fuel/air mixture. The intake port refers to the opening through which the mixture enters the cylinder, and the intake valve regulates that mixture's entry. In contrast, the intake manifold serves as the distribution hub for the mixture before it reaches the individual cylinders, making it the correct answer in this context.