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: Anatomy
[{'content': 'Level of lower border of lung at mid axillary line is \nSelect and explain. \nA. 6th rib, B. 8th rib, C. 10th rib, D. 12th rib', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. 8th rib', 'role': 'assistant'}]