In which of the following ways would you change the glass sample to make the ion exchange more efficient?

Question

a)Change the composition of the glass to increase the proportion of B2O3.
b)Change the composition of the glass to add Na2O, Li2O, or MgO.
c)Change the composition of the glass to add CaO.
d)Change the composition of the salt bath (KCl) to an ion smaller than potassium, such as sodium chloride (NaCl).
e)Lower the temperature of the salt bath to cool the sample more quickly.