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
Atwoods classification Order IV corresponds to 
Select and explain. 
A. Knife edged ridge, B. High well rounded, C. Low well rounded, D. Depressed
A: Knife edged ridge
Answer: A: Knife edged ridge 
Explanation: None