Answer:
c. Photosynthesis
Step-by-step explanation:
When forests are cut down, photosynthesis does not happen and as a consequence the carbon cycle is not started.
The carbon cycle begins when plants and other autotrophs absorb carbon dioxide from the atmosphere for use in photosynthesis. Photosynthesis and respiration lead the carbon from its inorganic phase to the organic phase and back to the inorganic phase, completing the biogeochemical cycle.