What detailed ecosystem process does the author illustrate, and what methods are utilized in order to clarify this process?

A.
The author describes the interaction between biotic and abiotic components of ecosystems, and clarifies this by giving specific examples of each type of component.

B.
The author narrates the process of strengthening biodiversity through studying ecosystems, and clarifies this process by discussing specific conservation strategies.

C.
The author describes the process of photosynthesis and how it links to the food chain, and clarifies this by sequentially explaining the roles of different organisms within this cycle.

D.
The author explains the process of purifying air and water, and makes it clear by explaining how different ecosystems provide this service.