This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Semen analysis of a male of an infertile couple shows the absence of spermatozoa but the presence of fructose. The most probable diagnosis is: 
Select and explain. 
A. Prostatic infection, B. Mumps orchitis, C. Block in efferent duct system, D. All of the above
C: Block in efferent duct system
Answer: C: Block in efferent duct system 
Explanation: The efferent ducts may be obstructed by an infection like tubercular, gonococcal or by surgical trauma following vasectomy.
The absence of fructose suggests the congenital absence of seminal vesicle or portion of the ductal system or both