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
The most common cause of epididymitis is 
Select and explain. 
A. Gonococcal infection, B. Chlamydia infection, C. Proteus infection, D. Tubercular infection
B: Chlamydia infection
Answer: B: Chlamydia infection 
Explanation: Epididymitis is most common in young men ages 19 to 35. Chlamydia is the most common cause in sexually active men younger than 35 years (accounting for up to 50% of cases). Infections with urinary coliforms (eg, E coli, Pseudomonas species, Proteus species, Klebsiella species) are the most common cause in children and in men older than 35 years. Reference : page 1383 Bailey and Love's sho practice of surgery 25th edition