In some areas of the world, like California and Japan, earthquakes are a common occurrence. How can this best be explained?

AThe strong ocean currents are undermining both areas causing earthquakes.

BBoth areas are subjected to strong ocean wind and waves that causes earthquakes.

CBoth areas are located near the edge of the Pacific Ocean, the unstable sand causes earthquakes.

DBoth areas are on the boundary of active plate margins, the motion of the plates causes earthquakes.