The correct option is C Sublimation
Sublimation separates a mixture of solids, one of which changes directly from a solid to vapour on heating without going through the liquid state. This change is called sublimation. On cooling, the vapour changes back to solid directly. Iodine is a solid that sublimes. When a mixture of iodine and sand is heated in a beaker, the iodine changes from solid to vapour directly.