In the given reaction, Zinc (Zn) has undergone a chemical change where it has combined with oxygen from carbon dioxide (CO2) to form Zinc oxide (ZnO). However, Zinc has not gained or lost electrons, and therefore its oxidation state has not changed. In other words, Zinc has not been oxidized or reduced, and it has not displaced any other element in the reaction, so it has not been a participant in a displacement reaction. Therefore, the correct answer is that Zinc has not been decomposed, displaced, oxidized or reduced in this reaction.