This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Non communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Crude bih rate is a simplest measure of feility because it includes \nSelect and explain. \nA. Total population, B. Mid year population, C. Live bihs only, D. Pre term bihs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Crude bih rate : Number of live bihs in a year per 1000 mid-year population CBR is simplest indicator of feility : Total mid-year population is not exposed to Child bearing thus it doesnot give true idea of feility Ref: Park 25th edition Pgno : 539', 'role': 'assistant'}]