This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
Which enzyme is not release as proenzyme? 
Select and explain. 
A. Pepsin, B. Amylase, C. Trypsin, D. Chymotrypsin
B: Amylase
Answer: B: Amylase 
Explanation: Ptyalin(alpha amylase) aids digestion of starch to produce dextrin and maltose. Ref.Textbook of physiology by AK Jain 7th edition page no.209