Answer:D physical chemistry
Explanation:when a matter undergo changes i.e transit from one form to another is a study that falls under physical chemistry,basically those changes can be seen,for example water at temperature below 0^°c is seen as ice,a solid structure completely different in structure, characteristics from water while at 100^°c ,it forms vapor a gas .this process involves latent heat and heat capacity and can be actually calculated to understand the mechanism involved.
