In the photochemical smog, there is formation ofNO,O3,NO2 and CH2O. The airborne pollutant mixtures ofnitrogen oxides and hydrocarbons on reacting with solarradiation lead to a type of air pollution known as photochemicalsmog. The reactions should involve oxidation and reduction. Thus the reactions that occur in photochemical smog are b,c andd, that is option (1)