Animals Have Enzymes That Break Apart Starch Molecules but Not

Animals have enzymes that break apart starch molecules but not cellulose, despite the fact that both are made up of glucose subunits. Which enzyme characteristic best explains this?

A) Enzymes are not permanently changed by the reactions they promote.
B) All enzymes are proteins.
C) Enzymes are highly specific.
D) Enzyme activity is regulated.
E) Enzymes usually speed up chemical reactions.