This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Histamine, 5-HT and PGs, Subject name: Pharmacology
[{'content': 'Aspirin is used for secondary prevention of ischemic hea disease because it:- \nSelect and explain. \nA. Inhibits TXA2 synthesis by platelets, B. Inhibit prostacyclin synthesis, C. Inhibits release of EDRF, D. Inhibit synthesis of endothelins', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Aggregatory substances: TXA2 ADP Inhibits aggregation: PGI2. Aspirin is Irreversible inhibitor of COX - thus preventing TXA2 formation & aggregation of PLATELETS.', 'role': 'assistant'}]