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
Which of the following is the important factor to be considered before attempting to close a midline diastema using a removable appliance? 
Select and explain. 
A. The size of the teeth, B. Age of the patient, C. Vitality of the teeth, D. Amount of overjet
B: Age of the patient
Answer: B: Age of the patient 
Explanation: None