Concept:Wind deposition in deserts mainly forms sand dunes, including crescent-shaped barchans.Explanation:A butte is a flat-topped rock hill left behind by erosion, not by wind deposition.A yardang is a streamlined ridge that is carved out by wind erosion.A wadi is a dry river valley that is shaped by water erosion.A barchan is a crescent-shaped sand dune that forms when wind deposits sand.Among the given options, only a barchan is a direct product of wind deposition.Answer:D. Barchan