Juanita wants to learn about the way clay swells when it is wet and shrinks when it dries. She gets a sturdy wooden box and fills it most of the way with clay. She buries a few hard-boiled eggs in the clay. Juanita pours water into the box and lets it soak into the clay. She lets the clay dry out, then she carefully removes it from the box one layer at a time. She finds that the egg shells have all been crushed. If the eggs in Juanita's experiment represent rocks in the real world, her experiment shows how swelling clay can cause A. weathering. B. deposition. C. frost heaves. D. erosion.