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: Surgery
[{'content': '40-year-old men are suffering from fever & pain in the scrotum which is not relieved by elevation of the testis. 3 days before had sexual contact with a young female - \nSelect and explain. \nA. Testicular tumour, B. Acute epididymitis, C. Torsion of testis, D. Acute orchitis', 'role': 'user'}, {'content': "Answer: C \nExplanation: Torsion of testis can be differentiated from acute epididymitis by Prehn's sign. ie\n\nOn the elevation of testis the pain increases in → Torsion\nOn the elevation of the testis, the pain decreases in → epididymoorchitis.\nDon’t be confused with fever, it can also occur in torsion, especially in older patients.", 'role': 'assistant'}]