Which type of solution is characterized by having less solute than the maximum solubility allows?

A solution that is characterized by having less solute than the maximum solubility allows is known as an unsaturated solution. In this type of solution, more solute can be dissolved in the solvent without exceeding the solubility limit. This means that if you were to add additional solute to an unsaturated solution, it would continue to dissolve until it reaches saturation. The key aspect of an unsaturated solution is its capacity to dissolve additional solute, reflecting that it is not yet fully saturated.

To provide context, a saturated solution contains the maximum amount of solute that can be dissolved at a given temperature and pressure. A concentrated solution generally refers to one with a high amount of solute relative to the solvent, but it does not specifically indicate whether it is saturated or unsaturated. A supersaturated solution contains more solute than what can typically dissolve at a given temperature, which is an unstable state that can lead to crystallization. Therefore, the defining feature of an unsaturated solution is its ability to dissolve more solute, making it the correct identification in this scenario.