Answer:- b) unsaturated
explanations:- From solubility curve, 108 g of potassium nitrate are soluble per 100 g of water (100 cubic centimeter).
So, if exactly 108 g of potassium nitrate are dissolved in 100 [tex]cm^3[/tex] of water then solution will be saturated. If less than 108 g of potassium nitrate are dissolved then solution will be unsaturated and if greater than 108 g of potassium nitrate are dissolved then solution will be super saturated.
Since, only 100 g of potassium nitrate are dissolved per 100 [tex]cm^3[/tex] of water, the solution is unsaturated.