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': 'Incidence of absent of kidney is \nSelect and explain. \nA. 300, B. 1500, C. 3000, D. 5000', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (1500) (1305-LB) (1286-B & L 25th)* An absent or grossly atrophic kidney is found in about 1:1400 individuals (1305-LB)* Renal ectopia - In approximately 1:1000 people, the kidney does not ascend, ectopic kidneys are usually found near the pelvic brim (1306-LB)', 'role': 'assistant'}]