This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
In low dose aspirin acts on 
Select and explain. 
A. Cyclooxygenase, B. Thromboxane A2 syntahse, C. PGI2 synthase, D. Lipooxyngenase
A: Cyclooxygenase
Answer: A: Cyclooxygenase 
Explanation: Refer KDT 6 /e p 609 Aspirin acts by inhibiting the enzyme cyclooxygenase