This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Aplastic anemia can progress to all except - \nSelect and explain. \nA. AML, B. Myelodysplastic anemia, C. Pure red cell aplasia, D. Paroxysmal nocturnal hemoglobinuria', 'role': 'user'}, {'content': 'Answer: C \nExplanation: PNH is the only hemolytic anemia caused by an acquired intrinsic defect in the cell membrane. PNH arises in the setting of aplastic anemia and these patients are at increased risk of developing acute myelogenous leukemia.\nAplastic anemia may progress to PNH and MDS.', 'role': 'assistant'}]