Which among the following is incorrect about amino acids?

• A. Amino acids are those that contain an amine group and a carboxylic group
• B. Base on the position of amino group with respect to the carboxylic group, amino groups are classified as α-, β-, γ-, δ- amino acids
• C. Proteins on hydrolysis produce α-, β-, γ-, δ- amino acids
• D. Amino acids are usually represented by a three letter symbol or a one letter convention