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
Patient has difficulty in swallowing as a CD wearer. The most probable cause is: 
Select and explain. 
A. Decreased vertical dimension, B. Increased vertical dimension, C. Thickness of flange, D. Decreased retention
B: Increased vertical dimension
Answer: B: Increased vertical dimension 
Explanation: None