Answer:
The correct answer to the question is sublimation i.e the change of phase from solid to gas is called sublimation.
EXPLANATION:
Before answering the question, first we have to understand various changes of states of matter.
There are various state changes or phase changes in nature.
Melting: Melting is the heat phenomenon in which substance in solid phase is converted into liquid at its melting point. For instance, ice converted into water.
Sublimation: Sublimation is the type of phase change in which solid substance is directly converted into gas without melting. For instance, the vaporization of camphor.
Vaporization: Vaporization is the type of phase change of matter in which a liquid substance is converted into gas at its boiling point. For instance, boiling of water.
As per our question, the change is occurring from solid to gas.
Hence, the phase change will be sublimation.
