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': 'Emergency retentive force for the maxillary complete denture is: \nSelect and explain. \nA. Posterior palatal seal., B. Base of the tongue., C. Soft palate., D. Deep palate.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Base of the tongue provides emergency retentive force.', 'role': 'assistant'}]