Concept:Water in deserts creates features by erosion or deposition; a wadi is formed by running water.Explanation:Desert landforms can be produced by wind or water.Zeugens and yardangs are sculpted by wind erosion.Barchans are crescent-shaped sand dunes formed by wind deposition.A wadi is a dry riverbed or valley that carries water only after heavy rainfall.So, wadis are directly produced by water in desert areas.Answer:Option B. wadis