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 NSAID undergoes enterohepatic circulation ? \nSelect and explain. \nA. Phenylbutazone, B. Aspirin, C. Ibuprofen, D. Piroxicam', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Piroxicam is a long acting analgesic due to enterohepatic\xa0circulation. Single daily dose is usually sufficient.', 'role': 'assistant'}]