This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NSAIDs, Gout and Rheumatoid Ahritis, Subject name: Pharmacology
[{'content': 'NSAID lacking anti-inflammatory action is: \nSelect and explain. \nA. Paracetamol, B. Ibuprofen, C. Diclofenac sodium, D. Celecoxib', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Paracetamol or acetaminophen has antipyretic and analgesic activities but it lacks anti-inflammatory action. It is presumed to become inactive by peroxides generated at the site of inflammation. Some theories suggest that PCM acts on COX-3 receptors.', 'role': 'assistant'}]