Correct option is (a) Chymosin
Explanation: Casein is hydrolyzed to para-k-casein and caseino macropeptide by using chymosin which belongs to class of hydrolases. Glucose oxidase oxides glucose to D-glucono-1, 5-lactone. Alanine aminotransferase transfers amino group from alanine to form glutamate whereas histidase removes amino group from histidine to form urocanate.