In the redox reaction $$2\text{MnO}_4^- + 5\text{C}_2\text{O}_4^{2-} + 16\text{H}^+ \rightarrow 2\text{Mn}^{2+} + 10\text{CO}_2 + 8\text{H}_2\text{O}$$, 20 mL of 0.1 M $$\text{KMnO}_4$$ react quantitatively with

A

20 mL of 0.1 M oxalate

B

40 mL of 0.1 M oxalate

C

50 mL of 0.25 M oxalate

D

50 mL of 0.1 M oxalate