This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urethra & Penis, Subject name: Surgery
A 46-year-old man has a swelling in the scrotum. It shows clear transillumination anterior to the testis when a light is applied to the scrotum in a dark room. This physical exam is most consistent with? 
Select and explain. 
A. Cyst of the epididymis, B. Torsion of testis, C. Hydrocele, D. Direct inguinal hernia
C: Hydrocele
Answer: C: Hydrocele 
Explanation: In adults, this is diagnostic, but in children, transillumination is also seen in an indirect inguinal hernia. As epididymal cyst may transilluminate but is posterior to the testis.