Answer:
D. Asthenosphere
Explanation:
The theory of plate tectonics states that the lithosphere which is the solid outer crust of the earth contains segmented plates that shift to the asthenosphere. The asthenosphere is the upper part of the mantle that is molten in form.
So, the ability of the plates to move over to the asthenosphere, is an important feature of the plates. There are different points in the earth where the plates merge and separate.
