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': 'Most common site for endometriosis in urinary system is \nSelect and explain. \nA. Kidney, B. Ureter - lower segment, C. Bladder, D. Ureter - upper segment', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Bladder is most common site for urinary endometriosis.', 'role': 'assistant'}]