How is ozone formed in photochemical smog?

Polar stratospheric clouds facilitate the formation of .... .

Given below are two statements.
Statement $I:$ In polluted water,values of both dissolved oxygen and $BOD$ are very low.
Statement $II:$ Eutrophication results in a decrease in the amount of dissolved oxygen.
In the light of the above statements,choose the most appropriate answer from the options given below.

Methemoglobinemia ('blue baby' syndrome) disease is associated with

Which of the following is not correct about carbon monoxide $(CO)$?

Mention the types of atmospheric pollution.