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 most important cause of failure of patient to wear RPD is due to: 
Select and explain. 
A. Indifferent patient education, B. Faulty laboratory procedures, C. Poor framework design, D. Improper preliminary rehabilitative restorative procedures
D: Improper preliminary rehabilitative restorative procedures
Answer: D: Improper preliminary rehabilitative restorative procedures 
Explanation: None