Pick up the correct statement
A. CO which is major pollutant resulting from the combuistion of fuels in automobiles plays a major role in photochemical smog
B. Classica smog has an oxidizing character while the photochemical smog is reducing in character
C. Phototchemical smog occurs in dya time whereas the classical smog occurs in early morning hours
D. During formation of smog the level of ozone in the atmopsphere goes down
