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': 'Suboccipitofrontal diameter is : \nSelect and explain. \nA. 9.4 cm, B. 10 cm, C. 11.3 cm, D. 12 cm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 10 cm', 'role': 'assistant'}]