This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
[{'content': 'Differential diagnosis of pancytopenia with cellular bone marrow include the following except \nSelect and explain. \nA. Megaloblastic anemia, B. Myelodysplasia, C. Paroxysmal nocturnal haemoglobinuria, D. Congenital dyserythropoietic anemia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Differential diagnosis of PancytopeniaPancytopenia with Hypocellular Bone MarrowPancytopenia with Cellular Bone Marrow1. Acquired aplastic anemiaPrimary bone marrow diseases1. Myelodysplasia2. Paroxysmal nocturnalhemoglobinuria3. Myelofibrosis4. Some aleukemic leukemia5. Myelophthisis6. Bone marrow lymphoma7. Hairy cell leukemia2. Constitutional aplastic anemia (Fanconi anemia, dyskeratosis congenita)3. Some myelodysplasiaSecondary to systemic diseases1. Systemic lupus erythematosus2. Hypersplenism3. B12, folate deficiency4. Overwhelming infection5. Alcohol6. Brucellosis7. Sarcoidosis8. Tuberculosis9. Leishmaniasis4. Rare aleukemic leukemia5. Some acute lymphoid leukemia6. Some lymphomas of bone marrowRef: Harrison; 19th edition; Page no: 663; Table no: 130-1', 'role': 'assistant'}]