Humans Can Digest Starch but Not Cellulose Because

Humans can digest starch but not cellulose because

A) the monomer of starch is glucose,whereas the monomer of cellulose is glucose modified by the addition of a nitrogen-containing group.
B) humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose.
C) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose.
D) humans harbor starch-digesting bacteria in the digestive tract but not cellulose-digesting bacteria.