This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Adrenergic System, Subject name: Pharmacology
[{'content': 'Drug used in Benign Prostatic Hypertrophy is? \nSelect and explain. \nA. a1agonist, B. a1. antagonist, C. a2, agonist, D. a2 antagonist', 'role': 'user'}, {'content': "Answer: B \nExplanation: ANSWER: (B) a, antagonistsREF: KDT 7th ed p-135, Goodman and Gillman's 11th ed page 172,173,183", 'role': 'assistant'}]