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
[{'content': 'Platelet adhesion is inhibited by ? \nSelect and explain. \nA. Nitric oxide, B. Substance P, C. Thrombin, D. IL 2', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Nitric Oxide", 'role': 'assistant'}]