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': 'Carrier stage seen in - \nSelect and explain. \nA. Polio, B. Cholera, C. Peusis, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans is d All of the above', 'role': 'assistant'}]