Which functional group is most susceptible to hydrolysis in drug metabolism?

Which functional group is most susceptible to hydrolysis in drug metabolism?

A. Alkane

B. Ester

C. Ether

D. Aromatic ring

According to the Biopharmaceutics Classification System (BCS), Class II drugs are:

A. High solubility, high permeability

B. Low solubility, high permeability

C. High solubility, low permeability

D. Low solubility, low permeability