Answer: Option (e) is the correct answer.
Step-by-step explanation:
When we add a non-volatile solute in a solvent then there will be decrease in its freezing point.
Also, when a substance is dissolved in a solution then ratio between actual concentration of particles and the concentration of a substance calculated from its mass is known as Van't Hoff factor.
Therefore, when we dissolve calcium chloride in water then each molecules of it will give one calcium ion and two chlorine ions. Whereas upon dissolution of NaCl we get one sodium ion and one chlorine ion.
Thus, we can conclude that a solution of calcium chloride, CaCl2, will lower the freezing point of water to a greater extent than an equal concentration of NaCl because the solution of calcium chloride produces more ions.