Which one of the statements given below concerning properties of solution, describes a colligative effect ?

Options

A. Boiling point of pure water decreases by the addition of ethanol.
B. Vapour pressure of pure water decreases by the addition of nitric acid
C. Vapour pressure of pure benzene decreases by the addition of naphthalene.
D. Vapour pressure of pure benzene increases by the addition of toluene.

Answer

C