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
According to Atwood residual ridge classiﬁcation order V denotes: 
Select and explain. 
A. High well-rounded ridge, B. Low well-rounded ridge, C. Knife-edge ridge, D. Depressed ridge
B: Low well-rounded ridge
Answer: B: Low well-rounded ridge 
Explanation: Order I – Pre-extraction-alveolus bearing tooth
Order II – Post-extraction-alveolus after extraction
Order III – High, well rounded-high alveolar process
Order IV – Knife-edge-High, narrow alveolar process
Order V – Low, well-rounded-rounded flat alveolar process
Order VI – Depressed-concave flat alveolar process.