A mixture of `NaHC_(2)O_(4) and KHC_(2)O_(4) .H_(2)C_(2)O_(4)` required equal volumess of `0.2 N KMnO_(4) and 0.12N NaOH ` separtely. What is the molar ration `NaHC_(2)O_(4) and KHC_(2)O_(4) .H_(2)O_(4)` in the mixture?
A. `6:1`
B. `1:6`
C. `1:3`
D. `3:1`