This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Which drug among the following does not inhibit platelet aggregation? \nSelect and explain. \nA. Aspirin, B. Celecoxib, C. Ibuprofen, D. Clopidogrel', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The\xa0selective\xa0COX-2 inhibitor (celecoxib) act primarily by inhibiting the cyclooxygenase enzymes that catalyze the first step in prostanoid biosynthesis. This\xa0leads\xa0to\xa0decreased\xa0prostaglandin\xa0 synthesis\xa0with\xa0both \u200bbeneficial\xa0 and\xa0 unwanted\xa0 effects.\xa0\u200b\nReference: Lippincott Illustrated Reviews: Pharmacology Wolters Kluwer Sixth Edition page no 451; \u200b', 'role': 'assistant'}]