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': 'After coming head of breech will have difficulty in delivery in all of the following conditions except: \nSelect and explain. \nA. Hydrocephalus, B. Placenta previa, C. Incomplete dilation of cervix, D. Extension of head', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]