Brad wants to learn about what happens to the materials that make up a plant after the plant dies. Which of the following could help Brad answer this question? A. Brad could go outside to look at trees and draw pictures of them in his notebook. B. Brad could ask all of his classmates to tell him their favorite kind of plant. C. Brad could plant a rosebush in a sunny area and measure how tall it grows. D. Brad could gather several dead leaves and watch what happens to them over several weeks.