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
The various habits of the lips can be divided into following, except: 
Select and explain. 
A. Lip sucking, B. Lip thrust, C. Lip insufficiency, D. None of the above
D: None of the above
Answer: D: None of the above 
Explanation: The various habits of the lips can be divided into following:

Lip sucking 
Lip thrust
Lip insuﬃciency