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
All are true about trauma from occlusion except 
Select and explain. 
A. Trauma to Marginalized gingiva, B. Reversible, C. Reduction in height of alveolar crest, D. No pocket
A: Trauma to Marginalized gingiva
Answer: A: Trauma to Marginalized gingiva 
Explanation: None