Answer;
2M CaCl2 because it will dissociate into 3 ions making the solute concentration and the greatest of the options
Step-by-step explanation;
-Osmotic pressure is the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution.
-CaCl2 is going to be higher because it dissolves into 3 particles, 2 Cl's and 1 Ca, whereas others like NaCl dissolves into only Na and Cl. so the concentration of CaCl2 is going to be higher.