The correct answer is D. More solute than it can dissolve at that temperature.

A supersaturated solution is a solution that contains more dissolved solute than it can hold at equilibrium at a given temperature. This means that the solution is unstable and can precipitate out the excess solute at any moment.

In contrast, a saturated solution (option C) contains as much dissolved solute as it can hold at equilibrium at a given temperature, while an unsaturated solution contains less dissolved solute than it can hold.