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 method of prepayment wherein the patient pays a percent of total cost: 
Select and explain. 
A. Loan, B. Co-insurance, C. Reasonable fee, D. Fee for service
B: Co-insurance
Answer: B: Co-insurance 
Explanation: None