At $T(K) , 100 L$ of dry oxygen is present in a sealed container. It is subjected to silent electric discharge , till the volumes of oxygen and ozone become equal. What is the volume (in liters) of ozone formed at $T(k)$?

Question

$$\begin {array} {1 1} (a)\;50 & \quad (b)\;60 \\ (c)\;30 & \quad (d)\;40 \end {array}$$