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': 'The largest presenting diameter in cephalic presentation is : \nSelect and explain. \nA. Biparietal diameter, B. Suboccipito bregmatic, C. Occipito frontal, D. None of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None of the above', 'role': 'assistant'}]