If you take a piece of white bread and chew it slowly for a long period of time, the flavor will become very sweet. This is due to the starch molecules in the bread being digested into smaller sugars that trigger a sweet sensation. Which substance is responsible for this breakdown

A) pepsin is breaking proteins into smaller fragments.
B) microvilli in the tongue are releasing sugars into the oral cavity.
C) pancreatic enzymes are releasing insulin.
D) amylase is breaking down starch to disaccharides.
E) peristalsis is occurring.