Which one of the following is produced during the formation of photochemical smog?

1. The question asks which substance is produced during the formation of photochemical smog. 2. Photochemical smog is formed when primary pollutants like Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs, including Hydrocarbons) react in the presence of sunlight. 3. These reactions produce secondary pollutants. 4. A major secondary pollutant formed in photochemical smog is ground-level Ozone (O3). 5. Other components include PAN (peroxyacetyl nitrate) and aldehydes. 6. While Hydrocarbons and Nitrogen Oxides are precursors (primary pollutants), Ozone is a key *product* formed during the photochemical reactions. 7. Methane is a hydrocarbon and greenhouse gas but not specifically the characteristic product of smog formation in this context. 8. Therefore, Ozone is the substance produced during the formation process. 9. The correct answer is (C).