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
Aspirin is used for ischemic heart disease: 
Select and explain. 
A. Inhibit TXA2 synthesis, B. Inhibit prostacyclin, C. Inhibit COX 2, D. Inhibit synthesis of endothelin
A: Inhibit TXA2 synthesis
Answer: A: Inhibit TXA2 synthesis 
Explanation: Ans. A. Inhibit TXA2 synthesisAspirin is irreversible COX inhibitor. At low dose 40-325mg they act as antiplatelet agent. They inhibit TXA2 synthesis which is platelet aggregator but also inhibit PGI2 which is platelet anti aggrator. But the net effect is TXA2 inhibition.