The chemical substance of photochemical smog responsible for eye irritation is

Which of the following statements about smog is correct?

List gases which are responsible for the greenhouse effect.

Given below are two statements :
Statement $I:$ The nutrient deficient water bodies lead to eutrophication.
Statement $II:$ Eutrophication leads to decrease in the level of oxygen in the water bodies.
In the light of the above statements,choose the correct answer from the options given below:

Which of the following molecules react with haemoglobin of the blood to produce toxic effect?

Consider the following reactions involving some atmospheric pollutants:
$NO + O_3 \rightarrow NO_2 + O_2$
$NO_2 \xrightarrow{h \nu} NO + O$
$O + O_2 \rightarrow O_3$
$4 NO_2 + O_2 + 2 H_2 O \longrightarrow 4 HNO_3$
$3 CH_4 + 2 O_3 \longrightarrow 3 H_2 C = O + 3 H_2 O$
Based on the above,the formation of formaldehyde from methane in the atmosphere will be controlled by: