This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
[{'content': 'Which of the following is an aromatase inhibitor? \nSelect and explain. \nA. Tamoxifen, B. Letrozole, C. Danazol, D. Taxane', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Letrozole is an orally active nonsteroidal compound that reversibly inhibits aromatization all over the body Letrozole, anastrozole, fadrozole, exemestane, formestane etc are aromatase inhibitors Ref Essentials of medical Pharmacology TD Tripathi 7th edition page no.314)', 'role': 'assistant'}]