In the enzyme chymotrypsin, why does Ser 195 develop a negative charge on its -OH group?
A. Negatively charged Asp COOresidue pulls the Ser–OH proton through His
B. Negatively charged Ser COOresidue pulls the Asp–OH proton through His
C. Positively charged Asp COOresidue pulls the Ser–OH proton through His
D. Positively charged Ser COOresidue pulls the Asp–OH proton through His