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: Surgery
[{'content': 'Prehn sign is seen in \nSelect and explain. \nA. Acute orchitis, B. Chronic orchitis, C. Testicular torsion, D. None', 'role': 'user'}, {'content': "Answer: C \nExplanation: Prehn's sign - elevation of the scrotum for 1 hr relieves the pain of acute epididymo-orchitis but aggrevates the pain in case of torsion testis . Reference : page 1082 SRB's manual of surgery 5th edition", 'role': 'assistant'}]