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': 'True about oral polio vaccine: \nSelect and explain. \nA. Poliomyelitis in recipients, B. Poliomyelitis in contact of recipient, C. Guillein Barre syndrome, D. Vomiting and fever', 'role': 'user'}, {'content': 'Answer: A \nExplanation: OPV has a rare complication of Vaccine associated paralytic Poliomyelitis (VAPP)\nIn vaccines: 1 in 1 million\nIn Close contacts of vaccines: 1 in 5 million', 'role': 'assistant'}]