Final answer:
The movement of Earth's tectonic plates is caused by convection currents in the asthenosphere, which is the result of heat transfer from the interior of the Earth causing the movement of plates that leads to various geological phenomena.
Step-by-step explanation:
The movement of Earth's plates is primarily driven by convection currents in the asthenosphere. This is part of the plate tectonics theory, which states that Earth's lithosphere is divided into tectonic plates that move around due to the mantle's viscous flow underneath them. As heat from the Earth's interior rises towards the surface, warmer material ascends due to its lower density while cooler material descends, creating a cycle that generates motion. These convection currents create enough force to move the plates over Earth's surface.
This process is vital to the understanding of geological phenomena such as earthquakes, continental drift, mountain building, and volcanic eruptions. The idea of subduction, mentioned in option B, is related but not the direct cause of the plates' movement; rather, it is one result of these movements at convergent plate boundaries.