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
Emergency retentive force for the maxillary complete denture is: 
Select and explain. 
A. Posterior palatal seal., B. Base of the tongue., C. Soft palate., D. Deep palate.
B: Base of the tongue.
Answer: B: Base of the tongue. 
Explanation: Base of the tongue provides emergency retentive force.