To solve this problem, we need to understand the reaction sequence given:$\\$1. The reaction starts with a Grignard reagent, $$RMgX, reacting with carbon dioxide, $$CO$_2. \\$2. This reaction forms a carboxylate salt, which is the intermediate compound $Y. \\$3. Upon hydrolysis with water, the carboxylate salt converts to a carboxylic acid, $$RCOOH.$\\$Let's analyze the reaction step-by-step:$\\$• The Grignard reagent, $$RMgX, is a strong nucleophile. It attacks the electrophilic carbon in $$CO$_2. \\$• The nucleophilic attack results in the formation of a carboxylate ion, $$RCOO$^-. \\$• The magnesium halide, $$MgX^+, associates with the carboxylate ion to form the salt } RCOO$^-$Mg$^+X. \\$Therefore, the compound $Y$ is the carboxylate salt $$RCOO$^-$Mg$^+X. \\$Upon hydrolysis, this salt reacts with water to form the carboxylic acid $$RCOOH.$\\$Thus, the correct option is Option 1: $$RCOO$^-$Mg$^+X. \\$