Josey wants to look at the cells of an onion under a light microscope. She peels off a thin, transparent layer of onion and places it on a microscope slide. Josey places the sample on the microscope stage, looks through the eyepiece, and adjusts the stage to focus the image. However, she is unable to see any details of the cells. Which of the following possible solutions could possibly help josey to see the onion cells in detail?.