I believe the answer is C, Sedimentary rock.
Hope this helps.
Answer: Amino acids; peptide
Explanation:
20 different AMINO ACIDS link together to form chains. A protein is composed of one or more of these PEPTIDE chains which are twisted and folded into a particular shape.
There exists 20 amino acids capable of forming protein in the Human body. At least two amino acids are joined together by a peptide bond to form polypeptide chains that are then held together by hydrogen bonds in twisted alpha helical structures to form proteins.
Bacteria cannot be classified using the biological definition of a species because they are asexual organisms, meaning they don't experience sexual feelings.
I hope this is the answer you were looking for and that it helps!! :)