The initial digestion of starch began in the mouth. Under the action of salivary amylase, some starch is converted into maltose, and the more you chew steamed bread in your mouth, the sweeter it becomes. Finally, under the action of pancreatic juice and intestinal juice, it is digested into glucose in the small intestine and absorbed by the human body. The more you chew steamed bread in your mouth, the sweeter it becomes. In this digestion process, the enzymes and digestive products involved are salivary amylase and maltose respectively.

So choose: B.