Carol and Maria spread some dirt out in a flat pan. Their classmate Ben blew over the dirt with a straw. Some of the dirt moved and formed ruts and bumps. They propped up one end of the pan with a board so the dirt looked like a big hill. Then the girls sprayed the dirt with some water in a spray bottle. More dirt moved as the water ran down the hill. Both the wind and the water modeled what process? A) decomposition B) erosion C) gravity D) weathering