Proteins are natural polymers composed of α-amino acids which are connected by peptide linkages.
The smallest unit to which the protein can be broken down is called amino acids. The α-amino acids are the amino acids whose one carbon contains both the amino group (NH2) and the carboxyl group (COOH). This type of carbon is called α-carbon. Thus, the amino acid that contains an α-carbon is called an α-amino acid.
Proteins upon acidic hydrolysis produce α-amino acids.
Hence, the answer is option B.