Respuesta :

Qu33nR3ckl3ss
First I would just like to point out that there is no following…..don't worry I did that once. HeHe
I think these are the following: 
A) N2→O2
B) N2+O2→2NO
C) CO2→NO2
D) H2O→H2S
And if so then the answer is B. Hope this helps.