Which of the following statements is $NOT$ in accordance with the fundamental principles of Green Chemistry?

$SO_2$ pollution is indicated by

London smog is found in

Formation of photochemical smog involves the following reactions in which $A$,$B$,and $C$ are respectively:
$(i)$ $NO_2 \stackrel{h\nu}{\longrightarrow} A + B$
$(ii)$ $B + O_2 \rightarrow C$
$(iii)$ $A + C \rightarrow NO_2 + O_2$
Choose the correct answer from the options given below:

The ozone layer exists up to $20 \ km$ above the Earth. Which of the following statements is true regarding the ozone layer and ozone?

Ultraviolet radiation breaks down $CFC$ molecules to produce .....