A geologist studies rocks. Which of Earth's spheres would a geologist be most interested in?

atmosphere

biosphere

hydrosphere

lithosphere

Lithosphere

Explanation:

The earth consists of the atmosphere, the biosphere, the hydrosphere and the lithosphere. The lithosphere refers to the solid part of the earth. Rocks are found both on the earth surface and below the earth surface. Rocks can only be found in the solid part of the earth known as the lithosphere and not in any other earth sphere. Hence the geologist is interested in the lithosphere.

The answer is lithosphere