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': 'The dose of OPV, given at birth, in case of institutional deliveries is - \nSelect and explain. \nA. Zero dose OPV, B. Initial dose, C. Primary dose, D. First dose', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]