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
NSAID lacking anti-inflammatory action is: 
Select and explain. 
A. Paracetamol, B. Ibuprofen, C. Diclofenac sodium, D. Celecoxib
A: Paracetamol
Answer: A: Paracetamol 
Explanation: 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.