A student is using a microscope to observe samples taken from pond water. She notices something that she thinks may be a living thing. Which argument would BEST support that the unknown sample is a living thing? A. The sample was moving, so it must be alive, because all living things respond to their environment.
B. The sample has cells, so it must be alive, because all living things are made up of one or more cells.
C. The sample is green, so it must be alive, because plants are green and they are alive.
D. The sample was producing bubbles, so it must be alive, because only living things can have chemical reactions that would release gases.