A Solution Is Sitting Undisturbed on a Side Shelf in the Laboratory

Multiple Choice

A solution is sitting undisturbed on a side shelf in the laboratory. A small crystal of the same solute of which the solution is made was gently dropped into the solution. Suddenly, a mass of crystals forms and settles to the bottom of the container. The solution is, or must have been

A) dilute.
B) concentrated.
C) unsaturated.
D) saturated.
E) supersaturated.