Jenny places a strip of pH paper into a solution. When she removes the pH paper, it has turned yellow-green. What should Jenny do next to determine the pH of her solution? A. place the pH paper into a machine that reads the pH of the solution b. compare the pH paper's color with the color of pH paper from another solution C. use a different testing method because the pH paper should not change colors D. compare the pH paper's color with a chart of colors and pH ranges