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': 'Voiding cysto urethrogram when viewed laterally, helps to diagnose all of following except \nSelect and explain. \nA. Vesicovaginal fistula, B. Ureterovaginal fistula, C. Urethro vaginal fistula, D. Urethral diverticulum', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Intra - venous pyelography is used to diagnose uretero vaginal fistula.', 'role': 'assistant'}]