This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': "Thoracic duct doesn't drain : \nSelect and explain. \nA. Right upper pa, B. Left upper pa, C. Left lower pa, D. Right lower pa", 'role': 'user'}, {'content': "Answer: A \nExplanation: Right upper pa drains lymphatics into the right lymphatic duct whereas the rest of the body drains into the thoracic duct. The thoracic duct is a continuation of cistern chyle as it pass through aoic hiatus at the level of T12. At T5, it crosses to left side and drains at left jugulosubclan venous angle at C5. Ref: Gray's Anatomy The Anatomical Basics of Clinical Practice 41 e pg 979.", 'role': 'assistant'}]