This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Testis and scrotum, Subject name: Surgery
[{'content': 'A 46-year-old man has a swelling in the scrotum. It shows clear transillumination anterioo the testis when a light is applied to the scrotum in a dark room. This physical exam is most consistent with? \nSelect and explain. \nA. Cyst of the epididymis, B. Torsion of testis, C. Hydrocele, D. Direct inguinal hernia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In adults, this is diagnostic, but in children,transillumination is also seen in an indirect inguinal hernai. As epididymal cyst may transilluminate but is posterior to the the testis', 'role': 'assistant'}]