All are particulate pollutants except

The correct option is B. Ozone.
In the presence of sunshine, interactions between primary nitrogen oxides and hydrocarbons produce ozone. It is a contaminant in the form of a gas. Particulate matter includes soot, flash, different forms of dust, fur, hair, spores, and other particles. They're divided into two categories: settleable and suspended particle matter. As a result, option B is the proper response.