Answer is c , because it's convection currents
The best quality answer I would say that it is cC
Force is a pull or a push acting on a body at rest or in motion resulting from its interaction with another body. Input force is the force that you put on a machine while Output force is the force the machine exerts on an object. The output distance is when the output force moves the machine a certain distance while the input distance is when the input distance is when the input force moves the machine a certain distance.