What are the two theories behind why tectonic plates move?

Mantle convection currents, ridge push and slab pull are three of the forces that have been proposed as the main drivers of plate movement (based on What drives the plates? Pete Loader). There are a number of competing theories that attempt to explain what drives the movement of tectonic plates.

Explanation:

all fossil fuels are nonrenewable, so think coal, gasoline, things that we will eventually run out of. all fossil fuels are nonrenewable resources, but not all nonrenewable recourses are fossil fuels. these resources are not being renewed as fast as we are using them. i hope this considering there weren't any answer choices.