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: Dental
[{'content': 'The ratio of skeletal: dental expansion obtained finally after Rapid palatal expansion is: \nSelect and explain. \nA. 4:01, B. 3:01, C. 2:01, D. 1:01', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]