To determine which reactions are disproportionation reactions, we need to understand the concept of disproportionation.$\\$A disproportionation reaction is a type of redox reaction in which a single substance is simultaneously oxidized and reduced, forming two different products.$\\$Let's analyze each option to identify if it is a disproportionation reaction:$\\$Option 1: Consider the reaction $$A$\rightarrow$B$+$C$. \\$In this reaction, if the oxidation state of element in A changes to different oxidation states in B and C, it is a disproportionation reaction.$\\$Option 2: Consider the reaction $$D$\rightarrow$E$+$F$. \\$Similarly, check if the oxidation state of element in D changes to different oxidation states in E and F.$\\$Option 3: Consider the reaction $$G$\rightarrow$H$+$I$. \\$Again, check for changes in oxidation states of element in G to different states in H and I.$\\$Option 4: Consider the reaction $$J$\rightarrow$K$+$L$. \\$Check for changes in oxidation states of element in J to different states in K and L.$\\$To identify a disproportionation reaction, follow these steps:$\\$• Determine the oxidation states of the relevant element in the reactant and products.$\\$• Verify if the element in the reactant is both oxidized and reduced in the products.$\\$After analyzing each option, we find that Option 1 is a disproportionation reaction.$\\$Therefore, the correct option is Option 1.