Q. PAN (Peroxyacetyl nitrate) is a secondary gaseous compound found in _?
Answer: Photochemical smog
Notes: Third option is the correct answer
Photochemical smog is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne particles and ground-level ozone.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 15 in Chemistry-4-Compounds in above course in App.