Answer: C.carbon dioxide
Explanation: Solution is a mixture containing solute and a solvent.
Solute is the component which is present in small amount. Solvent is the component which is present in larger amount.
Thus water acts as the solvent and [tex]CO_2[/tex] acts as the solute to form carbonic acid in all the carbonated beverages.
[tex]CO_2+H_2O\rightarrow H_2CO_3[/tex]