The concentration of oxalic acid is $'x' molL^{-1}$. 40 mL of this solution reacts with 16 mL of 0.05 M acidified $KMnO_4$. What is the pH of 'x' M oxalic acid solution ? (Assume that oxalic acid dissociate completely)

Question

$$\begin {array} {1 1} (a)\;1.3 & \quad (b)\;1.699 \\ (c)\;1 & \quad (d)\;2 \end {array}$$