Amino acids contain amino (−NH2) and carboxyl (−COOH) functional groups. Depending upon the relative position of the amino group with respect to the carboxyl group, the amino acids can be classified as α,β,γ,δ and so on. Only α−amino acids are obtained on the hydrolysis of proteins.
So, only in option (B) α-amino acid given all the other options are not α-amino acids.



