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': 'Bone marrow biopsy is absolutely indicated in which of the heamatological conditions? \nSelect and explain. \nA. Acute leukemia, B. Megaloblastic anemia, C. Hairy cell leukemia, D. Thalassemia', 'role': 'user'}, {'content': "Answer: C \nExplanation: All of the above options are indications for bone marrow examination. Since bone marrow cannot be aspirated in hairy cell leukemia, bone marrow biopsy becomes an absolute indication for establishing the diagnosis. Ref: Harrison's Principles of Internal Medicine, 16th Edition, Page 652; Davidson's Principles and Practice of Medicine, 20th Edition, Page 1047.", 'role': 'assistant'}]