Concept:The Gezira scheme and the Manaquil Extension are major irrigation projects in Sudan focused on crop production.Explanation:These schemes are located in the Nile Basin.They rely on irrigation from the Blue Nile and the Atbara River.Their main crop is cotton, which thrives in the region's fertile clay soil and warm climate.For this reason, the area is historically known for large-scale cotton farming.Answer:A. cotton