This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Demography and family planning, Subject name: Social & Preventive Medicine
[{'content': 'Male to Female ratio is \nSelect and explain. \nA. Males for 1000 popultaion, B. Females for 1000 males, C. Males for 1000 females, D. Females for 100 males', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The number of females per 1000 males is known as sex ratio Sex composition is one of the basic demographic characteristic of the population Reference : Park&;s textbook of preventive and social medicine, 23rd edition, Page no: 482', 'role': 'assistant'}]