3600, PLEASE MARK AS BRAINLIEST!!!
Answer:
The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Since our planet and its atmosphere form a closed environment, the amount of carbon in this system does not change.
Explanation:
I'd say C. an allergic reaction. Mainly because lots of people are allergic to many things and many people intend to have seasonal allergies cause by plants. Hope it helps!