Select the statement that best describes how the process of plate tectonics circulates materials between the asthenosphere and the lithosphere. a. Some lithosphere becomes asthenosphere at mid-ocean spreading centers and reenters the lithosphere at subduction zones.
b. The materials that form the asthenosphere never mix with the materials that form the lithosphere.
c. Some asthenosphere becomes lithosphere at mid-ocean spreading centers and reenters the asthenosphere at subduction zones.