This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Anatomy
[{'content': 'Varicocele is common on left testis because \nSelect and explain. \nA. Left testicular vein drains into IVC which has high pressure, B. Left testicular vein drains into left renal vein which has high pressure, C. Left testis is lower situated, D. Compression of testicular vein by rectum', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Variocele formation has been attributed to one of the three primary factors : Increased venous pressure in left renal vein Collateral venous anastomoses Absent or incompetent valves in the internal spermatic vein. Ref : Bailey & Love 23/e p1273', 'role': 'assistant'}]