Given below are two Statements :
Statement I : Classical smog occurs in cool humid climate. It is a reducing mixture of smoke, fog and sulphur dioxide.
Statement II : Photochemical smog has components, ozone, nitric oxide, acrolein, formaldehyde, PAN etc.
In the light of the above statements, choose the most appropriate answer from the options given below.

Let us verify each statement individually.

Statement I: Classical smog occurs in cool humid climate. It is a reducing mixture of smoke, fog and sulphur dioxide.

This is correct. Classical smog (also called London smog or reducing smog) occurs in cool, humid climates. It contains smoke, fog, and $$SO_2$$. The $$SO_2$$ acts as a reducing agent, hence it is called reducing smog.

Statement II: Photochemical smog has components: ozone, nitric oxide, acrolein, formaldehyde, PAN, etc.

This is also correct. Photochemical smog (also called Los Angeles smog) is formed by the action of sunlight on nitrogen oxides and hydrocarbons. Its components include ozone ($$O_3$$), nitric oxide (NO), acrolein ($$CH_2=CHCHO$$), formaldehyde ($$HCHO$$), and peroxyacetyl nitrate (PAN).

Since both Statement I and Statement II are correct, the answer is Option A.