How do organisms contribute to the carbon cycle?
a. through metabolic processes
b. through the diffusion of hydrogen ions
c. by reflecting light
d. by splitting water molecules

A. Through metabolic processes.

Explanation:

Carbon is a chief component of the biomolecules present in the organisms. Also it is released in the form of product in the metabolic process called respiraton into the atmosphere. The plants take up carbon in the form of carbon dioxide from the atmosphere for conducting a metabolic process called photosynthesis. This maintains the balance of carbon in nature and in carbon cycle.

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