The answer is A, to my brain power ig B)
An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. Biotic factors include plants, animals, and other organism .
Cellular respiration releases stored energy and glucose molecules and converts it into a form of energy that can be used by cells