Festivals related to material chemistry

Chemistry is a basic natural science to study the composition, structure, properties and changing laws of matter, that is to say, chemistry is a science to study matter. Fireworks set off in festivals belong to chemical changes, plastic products are artificial materials belonging to chemical products, liquefied gas cooking is to release heat by burning liquefied gas, which belongs to chemical changes and heat release, and drugs belong to chemical research.

So choose C.