5) The troposphere of the Earth's atmosphere supports life because it contains A. Water, oxygen, carbon dioxide, other greenhouse gases
B. Water, nitrogen, helium, and argon
C. Water, oxygen, carbon monoxide, methane
D. Water, nitrogen, oxygen, carbon monoxide

I think its A

Explanation:

Because the reason why airplane have closed windows is because we can't breathe in carbon dioxide when we go up. Of course there is oxygen just not a lot as we go up. Why would there be helium in the air? We would sound weird when we skydive.

this website is for anybody really not just for girls just saying, also while a lot of males are mean and you know there are the few who are kind and then there's the nice-guys but then theirs also guys like me who are shy we don't get out much because there are people like you who exist who would most likely punch a guy in the face so next time just think about things before you post them to a website where guys and girls can see your question.