The carbon cycle, closely related to the cycling of oxygen throughout the environment, is tied to which of the following processes.

A) Photosynthesis

B) Condensation

C) The Rock Cycle

D) Residence time

The appropriate answer is A. Photosynthesis is tied to the carbon cycle because it is the process by which plants use carbon dioxide from the atmosphere to make food. The carbon cycle is essentially the movement of carbon between the biosphere, atmosphere, hydrosphere, and lithosphere. Photosynthesis occurs as an interaction between the atmosphere and the biosphere.