This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
[{'content': 'Allopurinol specifically inhibits which enzyme? \nSelect and explain. \nA. Xanthine oxidase, B. Arginase, C. Carbamoyl transferase, D. Urease', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ESSENTIALS OF MEDICAL PHARMACOLOGY;7TH EDITION;KD TRIPATHI;PAGE NO 216', 'role': 'assistant'}]