The number of \( \mathrm{S{=}O} \) bonds present in sulphurous acid, peroxodisulphuric acid and pyrosulphuric acid, respectively are:
\( 2, 4 \) and \( 3 \)
\( 2, 3 \) and \( 4 \)
\( 1, 4 \) and \( 3 \)
\( 1, 4 \) and \( 4 \)