Answer:
D making a conclusion as they are telling you what they found
Disease, competition, and predation.
C there your answer i hope it help
Im pretty sure its
A. Number of Organisms
B. Amount of Matter
A million sorrys if im wrong :(
I believe the answer for this would be B. Just using the process of elimination knocks out D and A, and plants make carbs not protein during photosynthesis :)