A mixture of $$HCOOH$$ and $$H_2C_2O_4$$ is heated with concentrated $$H_2SO_4$$. The gases produced were passed through KOH solution where their volume decreased by $$\frac{1}{6}$$. Ratio of two acids in the mixture is

A

$$1 : 4$$

B

$$4 : 1$$

C

$$1 : 1$$

D

data insufficient