It's called a nutrient.
Nutrients are well, something that all humans need to survive. A certain amount of nutrients keep humans alive and healthy, yet a lack of nutrients will cause them to become sick and slowly die.
Thus, making it so nutrients is a chemical substance that organisms require to live.
Hope this helps!
The answer is A. I did the assignment
cell :- cell is the basic structural and functional unit of life.
Atom :- everything in the universe is made up of atom.
If organisms that lived there before had exceeded the carrying capacity then the ecosystem would no longer be able to sustain life
