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': 'Smallest fetal diameter is : \nSelect and explain. \nA. Biparietal, B. Bitemporal, C. Submentobregmatic, D. Occipito frontal', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Bitemporal', 'role': 'assistant'}]