During which stroke of a four-stroke internal combustion engine is work done to the system of gases?

A. Exhaust stroke
B. Intake stroke
C. Compression stroke
D. Power stroke

is compression stoke, cortney u are wrong

I don't see how. The power stroke to me is when the small chamber of gasoline fires and the piston is driven down and drives the wheels. It appears to me that the system of gases is doing work on its surroundings.

C. Compression stroke

The stroke of a four-stroke internal combustion engine during which work is done to the system of gases is the power stroke. In this stroke, the compressed air-fuel mixture inside the cylinder is ignited by the spark plug. The combustion of the fuel creates a rapid expansion of gases, which creates pressure and forces the piston downward. This downward motion of the piston is what produces the mechanical work to drive the engine's crankshaft and ultimately power the vehicle. Therefore, the correct answer is D. Power stroke.

never mind the answer is D