A 15 year old high school student wishing to join the school’s football and basketball teams presents to your office for a sports physical. As a part of the physical, you perform a hernia check. You notice that his right scrotum is markedly larger than his left. He denies pain or tenderness, as well as fever, night sweats, and weight loss. On palpitation, you feel a fluid filled mass in the scrotum but can’t get above the mass with your fingers. What is your most likely diagnosis?

A. Hydrocele
B. Testicular tumor
C. Varicocele
D. Epidermoid inclusion cyst.