The vapour pressure of a liquid depends upon:
1. Nature of the liquid:
Nature of intermolecular forces of attraction between the molecules of the liquid dictates the extent to which they will be released as vapour. Weaker the forces, greater is the vapour pressure. Diethyl ether has higher vapour pressure than ethyl alcohol.
2. Temperature of the liquid:
As temperature increases, kinetic energy of liquid molecules increases and more molecules leave the liquid phase to become vapours. As a result, the vapour pressure increases.
Therefore, correct option is D).