Please choose the correct answer to the question: Two layers of sedimentary rock are exposed on the side of a hill. Only one of the layers has fossils. The lack of fossils in one layer of sedimentary rock is most likely due to

Answer1: changing environments. Answer2: volcanic activity. Answer3: changing rates of erosion. Answer4: evaporation of sea water.

Answer format: answer1/answer2/answer3/answer4