Answer: The correct answer is option (1).
Step-by-step explanation:
Decomposition: It is a chemical reaction in which one large molecules breaks down into small molecules.
Sublimation: It a physical process in which solid state changes directly into gaseous state with escaping liquid state.
Distillation: : It is separation technique which used to separate the liquids on the basis of their boiling points.
Vaporization: It is physical process in which liquid state changes to gaseous state.
Hence, from the above we can conclude that decomposition is a type of a chemical reaction.