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
Clinically vesicovaginal and ureterovaginal fistula are differentiated by : 
Select and explain. 
A. USG, B. IVP, C. Cystoscopy with dye, D. Methylene blue three swab test
D: Methylene blue three swab test
Answer: D: Methylene blue three swab test 
Explanation: Methylene blue three swab test