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: Pediatrics
[{'content': 'Measles is infectious during – \nSelect and explain. \nA. After 4 days of rash, B. 4 days before and 5 days after rash, C. Throughout disease, D. Only in incubation period', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Period of communicability for measles is 4 days before and 5 days after appearance of rash.', 'role': 'assistant'}]