10 ml of KMnO4 solution is mixed with excess of KI solution in acidic medium. The iodine hence liberated required 20 ml of Na2S2O3 solution for titration. If the molarity of KMnO4 solution is 0.05, Find molarity of Na2S2O3 solution.
(A) 1
(B) 1.25
(C) 5
(D) 4.5
