Cellulose and Starch Are Both Polymers of Glucose Units,but Most

Cellulose and starch are both polymers of glucose units,but most animals can only use starch as a source of carbohydrate in their diets.Why are most animals incapable of digesting cellulose?

A) Starch contains α linkages between carbons 1 and 4,where as cellulose contains β linkages between carbons 1 and 2.
B) The glucose units of cellulose are in the open chain form and cannot be hydrolyzed by the cyclic-sugar specific enzymes of animals.
C) The polymer of cellulose is simply too long to be completely digested by animals.
D) Most animals do not produce enzymes which are capable of hydrolyzing β linkages between cellulose.
E) This statement is incorrect.Most animals can digest cellulose.