The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A couple comes for evaluation of infeility. The HSG was normal but semen analysis revealed azoospermia. What is the diagnostic test to differentiate between testicular failure and vas deferens obstruction?   (A) Serum FSH   (B) Karyotyping   (C) Testosterone levels   (D) Testicular FNAC
['(A) Serum FSH <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Serum FSH \n (B) Karyotyping \n (C) Testosterone levels \n (D) Testicular FNAC <> possible answers', '  A couple comes for evaluation of infeility. The HSG was normal but semen analysis revealed azoospermia. What is the diagnostic test to differentiate between testicular failure and vas deferens obstruction? <> context@']