This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax- wall and Bronchopulmonary segment, Subject name: Anatomy
[{'content': 'Thoracic duct opens into: \nSelect and explain. \nA. Subclan vein, B. Internal jugular vein, C. Right brachiocephalic vein, D. Left brachiocephalic vein', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Thoracic duct is continuation of cysterna chyli. It passes through aoic hiatus beginning at lower border of T12 . At T5 it crosses to left side andopens into the left venous (jugulo-subclan) angle - junction of the left internal jugular and subclan vein, at the beginning of left brachio-cephalic vein.', 'role': 'assistant'}]