Final answer:
The propeller governor adjusts the fuel supply to the engine to respond to changes in the system RPM.
Step-by-step explanation:
The propeller governor responds to changes in the system RPM by adjusting the amount of fuel being supplied to the engine, which in turn affects the speed of the engine and the propeller. If the system RPM decreases, the propeller governor may increase the fuel supply to maintain the desired RPM, while if the system RPM increases, the propeller governor may decrease the fuel supply to slow down the propeller.