Solution: The essential amino acids are those that our bodies cannot synthesize and must be obtained from our food. Lysine and tryptophan are essential amino acids.  Non-essential amino acids are those that our bodies can synthesize.

Aromatic amino acids have a phenyl group linked to the amino acid chain and have an aromatic rind structure. Proteins are nitrogenous chemical molecules made up of a series of amino acids in a lengthy chain. So, the correct option is (c).