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': 'Antidote of Heparin is: \nSelect and explain. \nA. Sodium nitrite, B. Protamine sulphate, C. Thiosulphate, D. Coumarin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Protamine sulphate', 'role': 'assistant'}]