Answer : The correct option is, (3) change states of matter.
Explanation :
Latent heat : It is defined as the heat required to convert the solid into liquid or vapor and a liquid into a vapor without changing the temperature.
There are two types of latent heat.
(1) Latent heat of fusion
(2) Latent heat of vaporization
Latent heat of fusion : It is defined as the amount of heat energy released or absorbed when the solid converted to liquid at atmospheric pressure at its melting point.
Latent heat of vaporization : It is defined as the amount of heat energy released or absorbed when the liquid converted to vapor at atmospheric pressure at its boiling point.
Hence, latent heat is used to change states of matter.