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': 'Appliance of choice in cases with anteroposterior\nmaxillary deficiency is \nSelect and explain. \nA. Cervical pull headgear, B. Reverse pull headgear, C. Occipital pull headgear, D. Parietal pull headgear', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]