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: Social & Preventive Medicine
[{'content': 'Barrier method -a) Hormonal contraceptiveb) IUDc)  Condomd)  Diaphragm \nSelect and explain. \nA. ab, B. bc, C. bd, D. cd', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]