Final answer:
The correct answer is B) Crankshaft. It is the component that converts the engine cylinders' linear up-and-down motion into rotational motion within an internal combustion engine.
Step-by-step explanation:
The component in an internal combustion engine that changes the engine cylinders' up-and-down motion into a rotating motion is the crankshaft. During the operation of a four-stroke internal combustion engine, this process occurs in a cyclical manner. The steps include the intake stroke where air and fuel are mixed, the compression stroke where the mixture is compressed, the power stroke where ignition and work from gas expansion occur, and the exhaust stroke where spent gases are expelled.
Specifically, in the power stroke, when the air-fuel mixture ignites and creates high pressure, the piston is pushed down. This linear motion of the piston is converted into rotational motion by the crankshaft. The crankshaft is designed to handle the force exerted by the piston and use it to rotate, thus driving the vehicle's wheels or any other connected machinery.