Determine the volumes of 0.50 M benzoic acid and 0.50 M sodium hydroxide required to make 100.0 mL of a pH 3.38 buffer solution.
a. 50 mL each
b. 60 mL benzoic acid, 40 mL sodium hydroxide
c. 40 mL benzoic acid, 60 mL sodium hydroxide
d. 70 mL benzoic acid, 30 mL sodium hydroxide