# The smog is essentially caused by presence of

$\begin{array}{1 1}(a)\;O_2\;and\;O_3\\(b)\;O_3\;and\;N_2\\(c)\;Oxides\;of\;sulphur\;and\;nitrogen\\(d)\;O_2\;and\;N_2\end{array}$

The smog is essentially caused by presence of oxides of S and N
Hence (c) is the correct answer.