Choose the correct option for the total pressure (in atm.) in a mixture of 4 g O_2 and 2 g H_2 confined in a total volume of one litre at 0°C is:…

Choose the correct option for the total pressure (in atm.) in a mixture of $\displaystyle 4 \mathrm{~g} \mathrm{O}_2$ and $\displaystyle 2 \mathrm{~g} \mathrm{H}_2$ confined in a total volume of one litre at $\displaystyle 0$°C is : [Given $\displaystyle \mathrm{R}=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}, \mathrm{~T}=273 \mathrm{~K}$ ]