What causes the sea floor to move apart at a sea floor spreading center A density B continental drift C paleomagnetism D convection currents

Answer: D convection currents

Explanation:

The seafloor spreading is a phenomena that occurs due to liberation of heat from the convection currents generated in the mantle. It makes the earth crust more plastic and less dense. This happens at divergent plate boundaries. As the plates move apart, the less denser material rises. It leads to the formation of mountain and crust cracks.