Type of amino acids obtained by hydrolysis of proteins is :

Proteins are natural polymers composed of $\alpha$-amino acids which are connected by peptide linkages.

The smallest unit to which the protein can be broken down is called amino acids. The $\alpha$-amino acids are the amino acids whose one carbon contains both the amino group \left({NH}_{2}\right)$and the carboxyl group \left(COOH\right)$. This type of carbon is called $\alpha$-carbon. Thus, the amino acid that contains an $\alpha$-carbon is called an $\alpha$-amino acid.

Proteins upon acidic hydrolysis produce $\alpha$-amino acids.

Hence, the answer is option B.