This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lower limb, Subject name: Anatomy
[{'content': 'Hunterian perforator is at \nSelect and explain. \nA. Upper thigh, B. Mid thigh, C. Lower thigh, D. Knee', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref: BD Chaurasia Human Anatomy vol 2 pg 125,127.', 'role': 'assistant'}]