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
Which enzyme is irreversibly inhibited by aspirin? 
Select and explain. 
A. Lipooxygenase, B. Cyclooxygenase, C. Thromboxane synthase, D. Phospholipase
B: Cyclooxygenase
Answer: B: Cyclooxygenase 
Explanation: Ans. is 'b' i.e., Cyclooxygenase