To solve this problem, we need to identify which pteridophytes are heterosporous.$\newline$Heterospory is the production of two different types of spores by the sporophytes of land plants.$\newline$These spores are:$\newline$• Microspores: Small spores that develop into male gametophytes.$\newline$• Megaspores: Larger spores that develop into female gametophytes.$\newline$Among pteridophytes, only a few genera are known to be heterosporous.$\newline$Let's analyze the options:$\newline$• Option 1: Lycopodium and Selaginella$\newline$ - Lycopodium is homosporous (produces only one type of spore).$\newline$ - Selaginella is heterosporous.$\newline$• Option 2: Selaginella and Salvinia$\newline$ - Both Selaginella and Salvinia are heterosporous.$\newline$• Option 3: Psilotum and Salvinia$\newline$ - Psilotum is homosporous.$\newline$ - Salvinia is heterosporous.$\newline$• Option 4: Equisetum and Salvinia$\newline$ - Equisetum is homosporous.$\newline$ - Salvinia is heterosporous.$\newline$Therefore, the correct pair of heterosporous pteridophytes is Selaginella and Salvinia.$\newline$This corresponds to Option 2.