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
When a molar has no opposing tooth, it can become: 
Select and explain. 
A. Extruded, B. Intruded, C. Protruded, D. Retruded
A: Extruded
Answer: A: Extruded 
Explanation: None