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': 'Most common myeloproliferative disorder is \nSelect and explain. \nA. Polycythemia rubra vera, B. CML, C. CLL, D. Myelofibrosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Examples of Myeloproliferative diseases are Polycythemia rubra vera, Myelofibrosis, and Essential thrombocytopenia. Here CML and CLL are not Myeloproliferative diseases and out the rest two Polycythemia is more common. Reference : Davidaon, 23rd Edition, page no : 969.', 'role': 'assistant'}]