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
Dental lamina is active up to: 
Select and explain. 
A. 1 year, B. 2 years, C. 4 years, D. 5 years
D: 5 years
Answer: D: 5 years 
Explanation: Even after 5 years, it may be active in 3rd molar area after it has disappeared elsewhere. Remnants of dental lamina persist as epithelial pearls or islands within the jaws and gingiva.