The statement that is not true about ozone is:

Given below are two statements:
Statement $I$: An allotrope of oxygen is an important intermediate in the formation of reducing smog.
Statement $II$: Gases such as oxides of nitrogen and sulphur present in the troposphere contribute to the formation of photochemical smog.
In the light of the above statements,choose the correct answer from the options given below:

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$(a)$ $2 SO_{2(g)} + O_{2(g)} \rightarrow 2 SO_{3(g)}$	$(i)$ Acid rain
$(b)$ $HOCl_{(g)} \stackrel{h \nu}{\longrightarrow} \dot{O}H + \dot{Cl}$	$(ii)$ Smog
$(c)$ $CaCO_{3} + H_{2}SO_{4} \rightarrow CaSO_{4} + H_{2}O + CO_{2}$	$(iii)$ Ozone depletion
$(d)$ $NO_{2(g)} \stackrel{h \nu}{\longrightarrow} NO_{(g)} + O_{(g)}$	$(iv)$ Tropospheric pollution

Choose the correct answer from the options given below.

Green chemistry means such reactions which

Methane gas has a global warming potential approximately $25$ times that of which of the following gases?

Polar stratospheric clouds facilitate the formation of .... .