Answer:
https://www.ncbi.nlm.nih.gov/books/NBK279457/
Explanation:
all the stuff right here bud or girl GOOD LUCK
I would have to say the answer is C.
A is incorrect since hydrogen is not an air pollutant.
B is incorrect because ozone is most definitely one of the top.
And D has cyanide which is a chemical for suicide during wars.
Hope this helps!
D on Edge :) hope this helps