Colligative properties depend on:

1. The nature of the solute particles dissolved in the solution.
2. The number of solute particles in the solution.
3. The physical properties of the solute particles dissolved in the solution.
4. The nature of solvent particles.

HINT: It depends on the number of solute particles in the solution.
 
Explanation:
Colligative properties are those properties of solutions that depend on the ratio of the number of solute particles to the number of solvent particles in a solution, and not on the nature of the chemical species present.
Colligative property is used to determine the molecular mass of particle.