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: Medicine
[{'content': 'The agent of choice for controlling heparin induced bleeding is \nSelect and explain. \nA. Protamine sulphate, B. Injectable vitamin K, C. Whole blood, D. Fresh frozen plasma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]