To solve this problem, we need to match the given acids with their structural descriptions.$\\$Let's analyze each acid:$\\$A. Peroxodisulfuric Acid (H$_2$S$_2$O$_8$):$\\$• This acid contains two S-OH groups, four S=O groups, and one S-O-O-S linkage.$\\$• Therefore, it matches with III.$\\$B. Sulphuric Acid (H$_2$SO$_4$):$\\$• This acid contains two S-OH groups and two S=O groups.$\\$• Therefore, it matches with IV.$\\$C. Pyrosulphuric Acid (H$_2$S$_2$O$_7$):$\\$• This acid contains two S-OH groups, four S=O groups, and one S-O-S linkage.$\\$• Therefore, it matches with I.$\\$D. Sulphurous Acid (H$_2$SO$_3$):$\\$• This acid contains two S-OH groups and one S=O group.$\\$• Therefore, it matches with II.$\\$Based on the analysis, the correct matching is:$\\$A->III, B->IV, C->I, D->II$\\$This corresponds to Option 2.