Which component is primarily responsible for engine cooling?

The radiator is the key component responsible for engine cooling in an internal combustion engine. Its primary function is to dissipate heat from the engine coolant that absorbs heat as it circulates through the engine. As the coolant flows through the radiator, it passes through a series of tubes and is exposed to air flowing through the radiator core. This air cools the coolant down, allowing it to return to the engine and absorb more heat. This continuous circulation ensures that the engine maintains an optimal operating temperature, which is crucial for efficient performance and preventing overheating.

The other components mentioned play significant roles in the overall operation of the engine but are not directly responsible for the cooling process. The turbocharger improves engine efficiency and performance by forcing more air into the combustion chamber but does not cool the engine. The fuel injector delivers fuel to the combustion chamber for ignition and power output but has no cooling function. Lastly, the exhaust manifold directs exhaust gases away from the engine but does not participate in the engine cooling mechanism. Therefore, the radiator is integral to maintaining proper engine temperatures, making it the correct answer.