This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'The thoracic duct crosses the posterior mediastinum at the level of which veebral body \nSelect and explain. \nA. T5, B. T6, C. T7, D. T8', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Thoracic duct ascents through posterior mediastinum from the level of T12 to T5.Ref: BD Chaurasia; Volume 1; 6th edition; Pg no: 285', 'role': 'assistant'}]