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: Gynaecology & Obstetrics
[{'content': "Sampson's Theory proposed to explain endometriosis is \nSelect and explain. \nA. Embolization of menstrual fragments through lymphatic channels., B. Metaplastic changes in embryonal cell rests., C. Reflux of menstrual endometrium., D. Histogenesis by induction.", 'role': 'user'}, {'content': "Answer: C \nExplanation: Sampson's theory: Reflux of menstrual endometrium through fallopian tubes causes endometriosis.", 'role': 'assistant'}]