Final answer:
In an aqueous solution, the solute with the highest concentration of water will have the lowest vapor pressure.
Step-by-step explanation:
In a solution, the solute particles disrupt the formation of vapor from the solvent, reducing its vapor pressure. According to Raoult's Law, the vapor pressure of a solvent in a solution is equal to the vapor pressure of the pure solvent multiplied by the mole fraction of the solvent. Since the question mentions a 0.100 M aqueous solution, the solute is already dissolved in water. Therefore, the solute that will have the lowest vapor pressure is the one with the highest mole fraction of water.
Since all the solutes are aqueous, they are all dissolved in water. The mole fraction of water will be the same for all the solutions. Therefore, the vapor pressure will be lowest in the solution with the highest concentration of water, which is pure water.