The carbon is returned through what process A. Cellular respiration
B. Photosynthesis
C. Eating it
D. Abiotic process only

The correct answer is B

B. Photosynthesis is the process in which plants prepare their own food using carbon dioxide and water which are converted into glucose in the presence of sunlight along with the release of oxygen.

I’m not exactly sure what your trying to ask, but if it’s how an organelle is similar to a body system or a part a nucleus is like a in function. but i don’t fully understand what you’re trying to ask