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
How long should a palatal crib should be worn by a patient being extracted for thumb sucking habit 
Select and explain. 
A. One week, B. One month, C. Three months, D. Six months or longer
D: Six months or longer
Answer: D: Six months or longer 
Explanation: None