I'm not exactly sure which one but I do know that an acid and a base react in a aqueous solution to form water, so i would probably eliminate the ones that aren't aqueous solutions.
Its 4 dude i did this already
Answer:
First of all, it's KNO₃ not KNO.
Second, KNO₃ is neither an acid nor it is a base, infact, it is a salt and therefore it's neutral.
hope that helps...
