This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Medicine
[{'content': 'Which of the following is a live attenuated vaccine? \nSelect and explain. \nA. Recombinant Hepatitis B vaccine, B. Tetanus toxoid, C. Yellow fever vaccine, D. Salk vaccine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Recombinant Hepatitis B vaccine is a subunit type which is a highly purified vaccine by recombinant DNA technology . Tetanus toxoid is a modified bacterial toxoid. Inactivated polio vaccine or salk vaccine is a suspension of formaldehyde killed poliovirus grown in monkey kidney,human diploid or vero cell culture . Reference : Harrison20th edition pg 1078', 'role': 'assistant'}]