The correct answer is f sublimation.
Sublimation is the process in which a solid changes directly into a gas without first becoming a liquid. This phenomenon occurs under specific conditions of temperature and pressure. A common example of sublimation is dry ice, which is solid carbon dioxide. When exposed to air at room temperature, dry ice skips the liquid phase and transforms directly into carbon dioxide gas. Understanding sublimation helps clarify the different phase changes that materials can undergo, highlighting the unique behaviors of certain substances under varying environmental conditions.