The image below shows what occurs under Earth's surface in certain areas.
ocean floor
asthenosphere
What does the model demonstrate?
A. Tectonic plates are pushed apart due to steam caused by heat circulation in the asthenosphere.
B. In the asthenosphere, circulating heat expands the thickness of the crust of each plate.
C. In the asthenosphere, as heat circulates, plates are pushed upward causing seismic activity.
D. Tectonic plates are pushed apart partly due to convection currents moving through the asthenosphere.