Lysine and tryptophan are:

Proteins are made of amino acids. Lysine and tryptophan are amino acids.

Non essential amino acids are present in the body and are not supplied with the diet.

Lysine and tryptophan are present in very small amount in the body and when they are needed by the body they are supplied in the diet. Hence, they are known as essential amino acids.

Tryptophan is an aromatic amino acid but lysine has a straight chain.

Hence, (c) is the correct option.