Answer: Unequal distribution of heat within Earth.
Lithosphere plates can be defined as regions of Earth's crust and upper mantle that are fractured into plates that move across mantle. Earth is made of three layers outer is crust, middle is mantle and the inner one is core. The different layers has different properties. The movement of plates is caused due to the unequal distribution of the heat within earth. This unequal distribution of heat generates a force which is the driving force for the movement of lithosphere plates.
Step-by-step explanation: