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': 'The drug used in heparin overdose is: \nSelect and explain. \nA. Protamine sulfate, B. Phylloquinone, C. Ticlopidine, D. Clopidogrel', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Protamine sulfate is an antidote of heparin overdose whereas vitamin K is used as an antidote for warfarin toxicity.', 'role': 'assistant'}]