To solve this problem, we need to understand the role of acids in preventing hydrolysis of $$Fe$^{2+}$ ions during the preparation of Mohr's salt solution.$\\$Mohr's salt is a double salt of ferrous sulfate and ammonium sulfate, with the formula $$FeSO$_4 \cdot ($NH$_4)_2$SO$_4 \cdot 6$H$_2$O$. \\$The $$Fe$^{2+}$ ions in solution are prone to hydrolysis, which can lead to the formation of $$Fe(OH)$_2$ and subsequent oxidation to $$Fe$^{3+}. \\$To prevent this, an acid is added to the solution. The acid serves two main purposes:$\\$• It provides a low pH environment, which suppresses the hydrolysis of $$Fe$^{2+}$ ions.$\\$• It prevents the oxidation of $$Fe$^{2+}$ to $$Fe$^{3+}. \\$Among the given options, dilute sulfuric acid (Option 2) is the correct choice.$\\$Here's why:$\\$• Dilute sulfuric acid provides sulfate ions, which are common ions in the solution, helping to stabilize the $$Fe$^{2+}$ ions.$\\$• It maintains a low pH, preventing hydrolysis and oxidation.$\\$Other acids like dilute nitric acid and dilute hydrochloric acid are not suitable:$\\$• Dilute nitric acid can oxidize ${Fe}^{2+}$ to ${Fe}^{3+}$, which is undesirable.$\\$• Dilute hydrochloric acid can introduce chloride ions, which may lead to the formation of $$FeCl$_2$ and other side reactions.$\\$Concentrated sulfuric acid is too strong and can cause charring or other unwanted reactions.$\\$Therefore, the correct option is Option 2: Dilute sulfuric acid.