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
Resorption in case of ideal orthodontic tooth movement
should be 
Select and explain. 
A. Undermining, B. Frontal, C. Indirect, D. Necrotic
B: Frontal
Answer: B: Frontal 
Explanation: None