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
To avoid pocket formation distance between the finish line and alveolar crest should be: 
Select and explain. 
A. 0.5 mm, B. 1 mm, C. 1.5 mm, D. 2.5 mm
D: 2.5 mm
Answer: D: 2.5 mm 
Explanation: If the distance between finish line and the alveolar crest is less than 2mm, the restoration may lead to gingival. inflammation, loss of alveolar crest and pocket formation.