You are presented with the quiz "what causes iron in rocks to oxidize?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "chemical weathering causes iron in rock to oxidize" and "chemical weathering is the chemical disintigration of rocks". So, what's the best answer to the question?

OPT:
--a tree falling
--oxidation reaction
--exposure to cold
--chemical disintegration
--hydrogen and oxygen
--basic building blocks of life
--fissures of hot, acidic water
--flow of electrons
The answer is:
chemical disintegration