To solve this problem, we need to understand how the presence of certain substances can enhance the pollution caused by oxides of sulfur.$\newline$Oxides of sulfur, such as $SO_2$ and $SO_3,$ are significant air pollutants. Their effects can be exacerbated by the presence of other substances.$\newline$Let's analyze each option:$\newline$• Particulate matter:$\newline$ - Particulate matter can act as a surface for the adsorption of sulfur oxides, leading to the formation of acid aerosols.$\newline$ - This enhances the pollution potential of sulfur oxides by increasing their residence time in the atmosphere.$\newline$• Ozone:$\newline$ - Ozone can react with sulfur dioxide to form sulfur trioxide, which can further react with water to form sulfuric acid.$\newline$ - This process increases the acidity of the atmosphere and contributes to acid rain.$\newline$• Hydrocarbons:$\newline$ - Hydrocarbons can participate in photochemical reactions that produce secondary pollutants, but they do not directly enhance sulfur oxide pollution.$\newline$• Hydrogen peroxide:$\newline$ - Hydrogen peroxide can oxidize sulfur dioxide to sulfur trioxide, which then forms sulfuric acid.$\newline$ - This reaction contributes to acid rain and increases the environmental impact of sulfur oxides.$\newline$Based on this analysis, the substances that enhance the pollution due to oxides of sulfur are:$\newline$• Particulate matter (a)$\newline$• Ozone (b)$\newline$• Hydrogen peroxide (d)$\newline$Therefore, the correct option is Option 2: (a), (b), (d) only.