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 massive/moderate splenomegaly is seen in -a) Myelofibrosisb) Thalassemiac) PRVd) hairy cell leukemiae) CML \nSelect and explain. \nA. b, B. ad, C. ac, D. ab', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]