The correct answer would be #3.
Not always. If a child was surrounded by a good role model (adult), then yes, they would learn how to act against conflicts. If the child was surrounded by someone (an adult) who failed the conflict, then it could lead to the young child copying them and resulting in a bad situation.
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!
T give me brainliest pls :)