The answer is B. Symbiosis. Symbiosis is the relationship least commonly found in nature. Hope it helped you, and have a great day.
-Charlie
A peer is someone who is the same age as you, and they do not have to even know you. You might be friends, you might not. They might be a student that's in the same grade as you.
basically, a peer is a student that is around your age.
Proteins or polypeptides. (They are interchangeable)
Purpose mean intended or result end determination