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
A couple complains of primary infertility in spite of staying together for 4 years and having unprotected intercourse, all tests in a wife are normal. Semen analysis shows a volume of 0.8 ml/ sperm count is 0, fructose is absent what is done next? 
Select and explain. 
A. Testicular FNAC, B. Ultrasound for obstruction, C. Local palpation of vas, D. Karyotyping
B: Ultrasound for obstruction
Answer: B: Ultrasound for obstruction 
Explanation: This is probably a case of obstructive azoospermia.
In this condition we need to know the site and nature of blockage. 
Among the given options ultrasound is the best. 
Vasogram can also be done.