Which part increases the air entering the engine's cylinders?

The turbo is designed to increase the amount of air that enters the engine's cylinders. It accomplishes this by using exhaust gases to spin a turbine, which then compresses the incoming air. This process allows for a greater density of air to be introduced into the engine, enabling it to burn more fuel and ultimately produce more power. By forcing more air into the cylinders than would be possible through natural aspiration, a turbocharger enhances engine efficiency and performance.

The choke, on the other hand, is used primarily during engine startup to restrict the air flow and enrich the fuel mixture, which is more about facilitating combustion when the engine is cold than increasing air intake overall. The fuel lines are responsible for transporting fuel to the engine, but they do not affect the amount of air entering the cylinders. The air intake system does allow air into the engine but does not compress it; therefore, it lacks the performance enhancement provided by a turbo.