Does graphene come from natural materials? give an explanation

Actually graphene is not occurred in naturally.

Explanation:

graphene is a layer or a sheet which is extracted from graphite because graphite is layered material. most of the time famous scotch tape may produce graphene but you can't identify it without using electron microscope

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

i think that the answer is c