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 midpalatal suture is most likely to open at which of the following ages of expansion? \nSelect and explain. \nA. 18 years old, B. 13 years old, C. 25 years old, D. 55 years old', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]