Correct option is (b) Production of insulin
The best I can explain: Production of insulin from porcine insulin is represented in the diagram. The conversion of to human insulin is done by replacing the C-terminal alanine (β30) residue by a threonine. This is achieved by a single transpeptidation step which is catalyzed by trypsin using a carboxyl-protected threonine in an aqueous solution with an organic co-solvent. Later, the protective group is removed by mild hydrolysis and the product is purified by silica gel chromatography.