A mixture of `Na_(2)C_(2)O_(4)` and `KHC_(2)O_(4).H_(2)C_(2)O_(4)` required equal volumes of 0.2 M `KMnO_(4)` and 0.2 M NaOH separately for complete titration the mole ratio of `Na_(2)C_(2)O_(4)` and `KHC_(2)O_(4).H_(2)C_(2)O_(4)` in the mixture is
A. `(2)/(11)`
B. `(11)/(2)`
C. `(5)/(2)`
D. `(7)/(2)`