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': 'Length of thoracic duct is: \nSelect and explain. \nA. 20 cm, B. 25 cm, C. 30 cm, D. 45 cm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: In adults the thoracic duct, including the confluence of lymph trunks (or the cisterna chyli in the small propoion in whom the latter is saccular) is 38-45 cm in length and extends from the second lumbar veebra to the base of the neck.', 'role': 'assistant'}]