Answer:
D. Changing ozone to oxygen gas
Explanation:
As a rule of thumb, it is always noting that making putting a substance through physical changes like melting or boiling, evaporating involves breaking intermolecular bonds. On the other hand, making a substance undergo chemical changes involves breaking intramolecular bonds like ionic bonds and covalent bonds.
Oxygen being changed from ozone to oxygen is a chemical change and therefore requires breaking of the oxygen-oxygen double bonds
