A flue gas composing of $70\%N_2,15\%C{O}_2,5\%CO,$ and unreacted $O_2,$ is being vented at $50C.$ If the relative humidity of the flue gas is $70\%$ at ambient pressure, what is the percent of $O_2$ in wet basis?

A$.8\mathrm{.}6$

B$.3\mathrm{.}0$

C$.9\mathrm{.}5$

D$.9\mathrm{.}1$