An equimolar mixture of `Na_(2)C_(2)O_(4)` and `KHC_(2)O_(4)3H_(2)C_(2)O_(4)` required `V_(1)` litre of `0.1MKMnO_(4)` ion acidic medium for complete oxidation. The same amount of mixture required `V_(2)` litre of `0.2M NaOH` for complete neutralization. What os the ratio of `V_(1):V_(2)` ?
A. `4:7`
B. `10:7`
C. `8:7`
D. `2:7`