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: Gynaecology & Obstetrics
[{'content': 'To avoid conception D.M.P.A. is given : \nSelect and explain. \nA. Monthly internals, B. 3 -- monthly, C. 6 -- monthly, D. Yearly', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 3 -- monthly', 'role': 'assistant'}]