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': 'Secondary attack rate of peussis in unimmunization household contacts of peussis \nSelect and explain. \nA. 30%, B. 40%, C. 60%, D. 90%', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., 90% SAR of some impoant infectious diseases Measles Rubella Chicken pox Peussis Mumps 80% 90 - 95% -- 90% -- 90% 86%", 'role': 'assistant'}]