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': 'An example of chronic myeloproliferative disorder is \nSelect and explain. \nA. Neutrophilic leukemoid reaction, B. Essential thrombocythemia, C. Plasmacytosis, D. Hairy cell leukemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: <p>According to WHO classification of myeloid neoplasms,the diseases under myeloproliferative group are chronic myeloid leukemia ,chronic neutrophilic leukemia ,chronic eosinophilic leukemia ,polycythemia vera & essential thrombocytopenia.</p><p>Reference :Harsh mohan textbook of pathology sixth edition pg no 357.</p>', 'role': 'assistant'}]