In which of the following states can a solution exist?

A solution can exist in different states: solid, liquid, or gas, depending on the nature of the solute and solvent involved. The most common state of solutions encountered in everyday contexts is the liquid state, such as salt dissolved in water or sugar dissolved in coffee. However, solutions can also be found in a gaseous state, such as when a gas dissolves into another gas (like oxygen in nitrogen in the air).

Furthermore, solid solutions exist where different components blend at the atomic or molecular level, as seen in alloys like bronze, which is made of copper and tin. This versatility in states illustrates the ability of solutions to form in various environments and under varying conditions, taking into consideration factors such as temperature and pressure. Thus, the correct answer highlights the broad scope of solutions beyond just a single state, reflecting their dynamic nature in the realm of chemistry.