Answer: Surface materials breaks down into smaller pieces.
Explanation:
Erosion is the geological process in which the topmost layer of the soil is worn away and transported by natural forces such as wind or water. A process which resembles erosion is weathering, which lead to breaking down or dissolution of rocks, but does not involve movement of the rock or soil materials.
After erosion the layers at the top of the soil are also broken down to smaller bits by factors such as water and winds.
B. No since rusting is a chemical change it does not follow the law of conservation of mass.