The correct answer is (c) lactase
The best I can explain: Lactose is hydrolyzed to β-D-galactose by lactase which is a β-galactosidase. Rennet is an enzyme used to hydrolyze casein in milk and in used in cheese making. Papain is a proteolytic enzyme used in meat tenderization. Pullulanase cleaves only α-1,6-links to give rise to straight-chain maltodextrins.