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': 'Mechanism of action of Silodosin: \nSelect and explain. \nA. Alpha antagonist, B. Beta antagonist, C. Anticholinergic, D. PDE5 inhibitor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: MEDICAL THERAPY IN BPH * Alpha-blockers: (Prazosin, terazosin, doxazosin, tamsulosin, alfuzosin, silodosin) Relaxes smooth muscle & decreases urethral resistance. Side effects: ohostatic hypotension, dizziness, tiredness, retrograde ejaculation, rhinitis & headache. * 5-Alpha-reductase Inhibitors: (Finasteride, dutasteride, triptorelin pamoate)', 'role': 'assistant'}]