Which of the following is/are primary pollutant (s)

A) Ozone        B) SO₂    C) SO₃

D) NO₂          E) PBN     F) CO

A primary pollutant is an air pollutant emitted directly from a source e.g., carbon monoxide (CO), oxides of nitrogen (NO_x, NO), sulfur oxides (SO_x), SO2​, volatile organic compounds (VOCs) and particulate matter (dust, ash, salt particles). They further react in the presence of sunlight to form secondary pollutants such as ozone.