To change the pH of a solution containing a single acid/base couple from 2.0 pH units below
its pKa to 2.0 pH unit above its pKa, add...
a. 1.0 equivalent of a strong acid
b. 2.0 equivalents of a strong acid
c. 1.0 equivalent of a strong base
d. 2.0 equivalents of a strong base
e. 0.5 equivalent of a strong base