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': 'Dukoral is: \nSelect and explain. \nA. Oral cholera vaccine, B. Oral rotavirus vaccine, C. Oral typhoid vaccine, D. Ready to use therapeutic food', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dukoral is a monovalent cholera vaccine based on formalin and heat killed whole cells of vibrio cholerae 01 plus recombinant cholera toxin B subunit. Ref: Park 21st edition, page 211.', 'role': 'assistant'}]