What part of the car is responsible for cooling the engine?

The radiator plays a crucial role in cooling the engine by dissipating heat generated during the combustion process. As the engine runs, it produces a significant amount of heat, which can lead to overheating if not properly managed. The radiator circulates coolant—a mixture of water and antifreeze—through the engine block, absorbing the heat. The heated coolant then travels to the radiator, where it is cooled down by airflow, either from the vehicle's movement or from the cooling fans. This cooled coolant then re-enters the engine, allowing for a continuous cycle that maintains optimal operating temperatures and prevents engine damage due to overheating.

The other options do not serve this function. The exhaust manifold directs exhaust gases away from the engine, the bumper is primarily designed for protection and aesthetics, and the fuel tank stores gasoline or diesel for the vehicle's operation. None of these components are involved in cooling the engine, making the radiator the clear and correct choice.