Which of the following is true about convection in earth's mantle and tectonic plate motion?
a. evidence suggests that plate motion and mantle convection are related processes.
b. evidence suggests that mantle convection stops plate motion from occurring. c. plate motion and mantle convection do not relate to each other in any way.
d. plate motion and mantle convection are related processes, but they cannot occur at the same time.

A. Evidence suggests that plate motion and mantle convection are related processes

Explanation:

Convection simply means when more dense materials sink and less dense material rise.

In relation to mantle and plate movements the inner mantle which is a semi liquid allows the buoyancy and floating movement of the solid plate which include the oceanic and continental plates.  

Both mantle convection and plate movement are closely related because of how the mantle convection also contribute in breaking the solid lithosphere into plate resulting to several earth structures like fault etc.