This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Medicine
[{'content': 'Pawn ball megakaryocytes are characteristic of- \nSelect and explain. \nA. Myelodysplastic syndrome, B. idiopathic thrombocytopenic purpura, C. Thrombotic thrombocytopenic purpura, D. Chloramphenicol toxicity', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The term "Pawn Ball Megakaryocytes" has been used to describe a peculiar type of abnormal cell that can be found in bone marrow samples taken from some patients with the myelodysplastic syndrome (MDS). In the 1970s, the term "pawn ball megakaryocytes" came into colloquial usage among bone marrow morphologists . Ref Davidson 23rd edition pg 961', 'role': 'assistant'}]