C.
Developing a better vocabulary
Proteins consist of one or more polypeptide chains. Each polypeptide chain consists of smaller sub-units or amino acids that are linked together. Amino acids serve as the building blocks of polypeptides, and polypeptides serve as the building blocks of proteins
Hope that helped!!
Answer:
I believe C is correct, not quite sure though
ANSWER: A
i hope that helps or gives the right answer