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': 'Population explosion is define as population growth rate of more than- _____ per year \nSelect and explain. \nA. 2, B. 1.75, C. 1.8, D. 1.5', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]