Mr. Hernandez's class is investigating this soil sample to determine the different layers of the soil. Which TWO methods will BEST investigate the presence of organic material and rock in the soil? A The students could mix the soil with water to test for organic material in the soil. B The student can remove the top layer of soil to investigate the middle layers of the soil. C The student can remove the roots from the topsoil because the roots will affect the soil sample. D The student can use a screen to sift the soil to determine the amount of rocks in the soil to determine the layers. E The student can remove the rock layer from the bottom of the soil sample to investigate soil without the bottom layer of rock.