This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Prostate and seminal vesicles, Subject name: Surgery
[{'content': 'Fructose absence in semen analysis suggests: \nSelect and explain. \nA. Bilateral vas deferens obstruction, B. Seminal vesicles agenesis, C. Testicular failure, D. Prostatic urethral obstruction', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Abnormalities Low ejaculate volume may indicate: Retrograde ejaculation Ejaculatory duct obstruction Incomplete collection Androgen deficiency Azoospermia: Testicular failure Obstruction of vas deferens Absence of fructose: Seminal vesicle agenesis or obstruction', 'role': 'assistant'}]