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
Habits are classified into pressure and non pressure habits  by 
Select and explain. 
A. Morris and Bohanna, B. Kingsley, C. Klein, D. Finn
A: Morris and Bohanna
Answer: A: Morris and Bohanna 
Explanation: None