Chemistry - Biomolecules Question with Solution | TestHub

Amino acids contain amino ($-{\mathrm{NH}}_2$) and carboxyl ($-\mathrm{COOH}$) functional groups. Depending upon the relative position of the amino group with respect to the carboxyl group, the amino acids can be classified as $\mathrm{\alpha }, \mathrm{\beta }, \mathrm{\gamma }, \mathrm{\delta }$ and so on. Only $\mathrm{\alpha }-$amino acids are obtained on the hydrolysis of proteins. 

So, only in option (B) $\mathrm{\alpha }$-amino acid given all the other options are not $\mathrm{\alpha }$-amino acids.