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 of the following  is the longest acting NSAID? \nSelect and explain. \nA. Aspirin, B. Piroxicam, C. Ibuprofen, D. Acetaminophen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Piroxicam is the longest acting NSAID because of "enterohepatic recycling".', 'role': 'assistant'}]