Layers of shells from once-living organisms and sediment are cemented together and turn to rock, storing the carbon in stone called limestone. This process moves carbon atoms from the biosphere to the geosphere (lithosphere).

Sedimentation.

Explanation:

The process that is responsible for the movement of carbon atoms from the biosphere to the geosphere is called sedimentation. Carbon enters the geosphere or lithosphere through the biosphere when dead organic matter becomes incorporated into the soil that turns the shells of calcium carbonate to become limestone through the process which is called sedimentation. This sedimentation process is very necessary for the formation of different types of minerals such as limestone, fossil fuels etc.

i believe it would be c: tons.