Answer:
C. Motion of tectonic plates
Step-by-step explanation:
"Energy for Earthquakes comes from radioactive energy in Earth's mantle. Radioactive decay produces heat that causes convection in the mantle. This movement is transferred to Earth's crust where movement stores up energy in rocks, like a spring being stretched. They usually occur when rocks under stress suddenly shift along a fault (break in the crust of the earth along which movement occurred). Energy released radiates in all directions from its source (or focus). Energy is in the form of seismic wave."