Which sphere includes mountains and volcanoes?

• A. The geosphere.
• B. The atmosphere.
• C. The biosphere.
• D. The hydrosphere.

Answer: (A)

Mountains and volcanoes are features of the solid Earth, the geosphere. This sphere encompasses the rocks, minerals, landforms, and the interior structure of our planet—from the crust to the mantle. Volcanoes grow from magma that originates below the surface and erupts onto land, while mountains form when tectonic forces fold, uplift, or collide rock layers. The other spheres deal with different things: the atmosphere is the layer of gases surrounding Earth, the hydrosphere includes all water, and the biosphere covers living organisms and their environments. So the rugged features you see on land—mountains and volcanoes—fall squarely within the geosphere.