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
Which of the following shapes of the palatal vault is most favourable for lateral stability? 
Select and explain. 
A. V shape, B. U shape, C. Flat, D. (B) & (C)
B: U shape
Answer: B: U shape 
Explanation: None