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 internal rotation in mentoposterior position is : \nSelect and explain. \nA. 3/8th of circle, B. 2/8th of circle, C. 1/8th of circle, D. 3/4th of circle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 3/8th of circle', 'role': 'assistant'}]