Respuesta :
Answer:
It is carbon dioxide
Explanation:
All source relies on it Because if they dont have it then its not considered a source of anything else.
Carbon dioxide refers to the source of carbon that can be found in each of the four spheres.
What is Carbon dioxide?
This is an acidic colorless gas which are found in trace amounts in the ecosystem.
Plants use it to produce food and they act as sources of carbon thereby making it the most appropriate choice.
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