Answer:
Proteins.
Step-by-step explanation:
Amino acids are the monomers of the proteins. Proteins are one of the most important biomolecules of the living organisms. Two important types of amino acids are essential amino acids and non-essential amino acids.
Essential amino acids are not produced in our body and must be obtained from the external source. The diet should contains proteins to obtain the essential amino acids in the proteins as proteins are the polymers of amino acids.
Thus, the correct answer is option (a).