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 measles are all except ? \nSelect and explain. \nA. Koplik's spots is pathognomonic, B. Source is a case, C. Infectivity is low, D. Affect age group 1 to 3 years", 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Infectivity is low Measles has high infectivity with secondary attack rate of 80%. Other options are correct.", 'role': 'assistant'}]