Which of the following is least likely to dissolve in the polar solvent water?

Answer

ethanol

salt

sugar

oil

Like dissolves like and unlike repels like. This applies to the polarity of the solutions. Polar dissolves polar and non-polar does not mix with polar solutions. In this case, the polar substance that can mix with water. Sugar and salt can be dissolved through agitation. Oil which is nonpolar is immiscible in water. Hence answer is D.