AP Environmental Science

Answer: B - The mantle is the Earth zone that has the most volume and mass.

Key Takeaway: As the planet formed, dense, heavy materials sank toward the center of the Earth, while the less dense materials rose. This development into layers is known as planetary differentiation. The Earth is made up of several layers: at the center is the core (which includes the inner and outer core), then the mantle (comprised of the athenosphere), and lastly the lithosphere (made of the upper mantle and the Earth’s crust). As the largest portion of the Earth, the mantle has the most volume and mass. This dense layer makes up almost 70 percent of the interior of the Earth.