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
Apical migration of the epithelial attachment with corresponding recession of the marginal gingiva results in? 
Select and explain. 
A. A shallow sulcus, B. Gingival pocket formation, C. Infrabony pocket formation, D. Periodontal pocket formation
A: A shallow sulcus
Answer: A: A shallow sulcus 
Explanation: None