Out of PAN, H₂CO₃, H₂SO₄ and HNO₃ acid rain contains

Oxides of sulphur and nitrogen, when dissolved in rain water, they are converted into acid and thus are parts of acid rain.

$\begin{array}{l}{\mathrm{N}}_2{\mathrm{O}}_5\mathrm{\hspace{0.17em}}+\mathrm{\hspace{0.17em}}{\mathrm{H}}_2\mathrm{O}\mathrm{\hspace{0.17em}}\stackrel{ }{\to }\hspace{0.17em}\hspace{0.17em}2{\mathrm{HNO}}_3\\ {\mathrm{SO}}_3\mathrm{\hspace{0.17em}}+\mathrm{\hspace{0.17em}}{\mathrm{H}}_2\mathrm{O}\mathrm{\hspace{0.17em}}\stackrel{ }{\to }\hspace{0.17em}\hspace{0.17em}\underset{ }{{\mathrm{H}}_2{\mathrm{SO}}_4}\end{array}$