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': 'Thoracic duct commonly terminates in: \nSelect and explain. \nA. Internal jugular vein, B. External jugular vein, C. Brachio cephalic vein, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In rare individuals there is no apparent thoracic duct on the left. Several terminal openings are frequent (10-40%, according to different observers). Patterns vary greatly in different studies, but the commonly repoed sites of termination are internal jugular vein (36-48%), jugulo-subclan junction (35%) and subclan vein (9% and 17%). Termination in the left brachiocephalic vein occurs in 8%.', 'role': 'assistant'}]