In the reaction of KMnO4 with an oxalate in acidic medium, MnO4 is reduced to Mn2+ and C2O42- is oxidised to CO2. Hence, 50 mL of 0.04 M KMnO4 is equivalent to
(a) 100 mL of 0.1 M H2C2O4
(b) 50 mL of 0.2 M H2C2O4
(c) 50 mL of 0.1 M H2C2O4
(d) 25 mL of 0.1 M H2C2O4