This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney & Ureturs, Subject name: Surgery
[{'content': 'Yoyo reflex is seen in: \nSelect and explain. \nA. Duplication of ureter, B. Polycystic Kidney, C. Melluary sponge kidney, D. Pseudo Kidney', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Duplication of ureterRef Internet sources* Yo-Yo Reflex is seen in duplicated system of ureter* The ectopic ureter joins the normal ureter and may cause obstruction or reflex. This is known as Yo-Yo reflex', 'role': 'assistant'}]