The answer you need is B. Pollution. Have in mind that Caves contain carvings and depictions that are formed from acids running through the limestones of the cave. The sulfuric acid that helped form the Lechugilla caves come from pollution.I hope this info can help you
I am from Nepal i don't know this language
3Ba + Au3(PO)2 =Ba3(PO)2 + 3Au
