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': 'In IMR, age of infants is considered – \nSelect and explain. \nA. Below 1 month, B. Below 1 year, C. Upto 1 year, D. 28 days', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Infants are children less than 1 year of age.\n\nInfant mortality rate\n"The ratio of infant death in a year to the total number of live birth in that year. But it is usually expressed as a rate per 1000 live birth".', 'role': 'assistant'}]