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: Social & Preventive Medicine
[{'content': 'For inventing which one of the following is Marc Koska best known ? \nSelect and explain. \nA. Artificial blood, B. Disposable K1–syringe, C. Vaccine against Polio, D. ELISA test', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]