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?
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.
Testicular FNAC
Ultrasound for obstruction
Local palpation of vas
Karyotyping