What is Supersaturation? (I think its D. But i dont know)

A. Supersaturation occurs when a different solvent is added to a solvent, increasing how much can be dissolved.
B. Supersaturation occurs when natural water dilutes a solvent that also dissolves the solute at the same time.
C. Supersaturation occurs when a solvent's temperature is increased to increase the dissolving amount, then cooled to a normal temperature.
D. Supersaturation requires the use of powered solute, to increase the saturation point beyond the normal maximum.