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: Medicine
[{'content': 'Pancytopenia with cellular marrow is seen in all except - \nSelect and explain. \nA. Megaloblastic anemia, B. Myelodysplasia, C. Paroxysmal Nocturnal hemoglobinuria, D. G6PD deficiency', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]