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': 'Zero dose of Polio vaccine is which is given \nSelect and explain. \nA. Before giving DPT, B. At birth, C. When child is having Diarrhea, D. When child is having Polio', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]