The correct order of increasing acidic nature of SO2, SiO2 <P2O3 and Al2O3 is
The metallic character follows the order: Al>Si>P>S. The non-metallic character increases towards sulphur and oxides of non-metals are acidic nature. So the acidic nature increases as: (c) Al2O3< SiO2 < P2O3 < SO2