This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S., Subject name: Medicine
[{'content': 'Priapism can be due to? \nSelect and explain. \nA. C.M.L, B. Myelo-fibrosis, C. A.I.H.A., D. Thrombocytopenia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) C.M.LRef: Harrison 19th ed. / 324y 634Priapism is characterized by prolonged, painful and irreducible erection, not resulting in ejaculation. It is an emergency with a poor prognosis, as the risk of impotence is 50%.Causes of Priapism* Sickle cell anemia* Chronic myelogenous leukemia, Chronic lymphocytic leukemia, and acute lymphoblastic leukemia* Drugs', 'role': 'assistant'}]