Answer : A Disaccharidase
Acquired lactase deficiency is a widespread disorder of carbohydrate absorption. The symptoms of this disease typically begin in adolescence, when patients complain of flatulence and diarrhea after the ingestion of dairy products.
Lactose is one of the most common disaccharides in dairy products. The intestinal brush border contains disaccharidases that are important for cleavage of lactose to free glucose and galactose for absorption.
Congenital lactase deficiency is rare but may be lethal if not recognized.
The other choices do not hydrolyze lactose.