Concept:Crystallization depends on the change in a salt's solubility with temperature.
Explanation:When a hot saturated solution is cooled, the salt becomes less soluble in the cold solvent.
Excess salt then separates out as crystals.
If a salt's solubility increases considerably with temperature, cooling it produces a large amount of crystals.
Therefore, such a salt can be separated efficiently by crystallization.
A salt whose solubility changes little with temperature will not crystallize well on cooling.
Solubility directly affects whether crystallization will occur.
Answer:C. Crystallization would be efficient in separating out a salt whose solubility increases considerably with temperature.