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': 'The rate adjusted to allow for the age distribution of the population is \nSelect and explain. \nA. Age- standardized mortality rate, B. Peri-natal mortality rate, C. Fertility rate, D. Crude mortality rate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]