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: Radiology
[{'content': 'Tracheal bifurcation on X-ray corresponds to \nSelect and explain. \nA. T5T6, B. T4T5, C. Sternal angle, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A i.e. T5T6; B i.e. T4 T5; C i.e. Sternal angle', 'role': 'assistant'}]