This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Prostaglandins, Subject name: Pharmacology
Ibuprofen acts by inhibiting:(1994) 
Select and explain. 
A. Lipo oxygenase, B. Cyclo oxygenase, C. Resetting the hypothalamic thermostat, D. Increases the pain threshold
B: Cyclo oxygenase
Answer: B: Cyclo oxygenase 
Explanation: bRef: KDT, 5th ed, p. 176, 158 & 4th ed, p. 459, 460