You receive a sample slide of an organism. While observing it under a microscope, you notice that the organism is single-celled and green in color. There are multiple individual organisms on the slide. Based on this initial information, you guess that it is either a bacterium or a protist. Which trait is least likely to help you identify the correct group of this organism? (1 point)
A. the presence of different cell shapes
B. the presence of cell structures in the cell
C. the absence of a nucleus
D. the absence of cell structure membranes