Answer:
Lithosphere
Step-by-step explanation:
lithosphere is the only sphere that contains rock and that is the solid layer of Earth. Hydrosphere is from water. the biosphere is a portion of Earth in which living things live.T atmosphere is the envelope of gases surrounding the earth or another planet.
So the only option that make sense is lithosphere since it actually has rock in it and none of the others can possibly be studied for rocks.
(I hope this helps! Have a great day!)
:)