Which statement is true about oxygen and rocks? both are mixtures. both are pure substances. oxygen is a mixture and a rock is a pure substance. oxygen is a pure substance and rocks are mixtures.

B. both are pure substances

B? i feel like this is a trick  

Answer    "a salt" would be the best answerexplanationsalts can be defined as ionic compounds that are neither acids nor bases. nacl is an example of a salt, and its ionic.an enzyme is an organic compound which is covalently bonded, not ionically bonded.acids are generally held together by covalent bondsan element does not need any bonds to exist