Which of the Following Elements Is Involved in the Mechanism

Multiple Choice

Which of the following elements is involved in the mechanism of chymotrypsin?

A) deprotonation of an active site Asp residue by His to start the reaction
B) formation of an acyl-enzyme intermediate that must be hydrolyzed to complete the reaction
C) stabilization of the positively charged His by a Gln residue
D) direct deprotonation of water by His to generate a hydroxide ion for initiation of the reaction