Answer:
Amino acids.
Explanation:
Amino acids may be defined as the chemical molecule that contain both the amino group and carboxylic group. The amino acids mainly consists of carbon, hydrogen, nitrogen and oxygen.
Proteins are the polymers of amino acids. Amino acids acts as monomer and when repeated together form a particular protein. The amino acids are linked together through peptide bond in protein.
Thus, the correct answer is option (3).
