For the redox reaction,
`MnO_(4)^(-) + C_(2)O_(4)^(2-) + H^(+) rarr Mn^(2+) + CO_(2) + H_(2)O`
the correct coefficients of the reactants for the balanced reaction are

Explanation

Oxidation reaction : `C_(2)O_(4)^(2-) rarr 2CO_(2) + 2e^(-) ] xx 5`
Reduction reaction : `MnO_(4)^(-) + 8H^(+) + 5e^(-) rarr Mn^(2+) + 4H_(2)O ] xx 2`
Net reaction : `2MnO_(4)^(-) + 16 H^(+) + 5 C_(2)O_(4)^(2-) rarr 2Mn^(2+) + 10CO_(2) + 8H_(2)O`