How do you compute for this?

9. The Houser Company has negotiated a $500,000 revolving credit agreement with Chitwood National Bank. The agreement calls for an interest rate of 10% on fund used, a 15% compensating balance, and a commitment fee of 1% on the unused amount of the credit line. Assuming that the compensating balance would not otherwise be maintained, the effective annual interest cost if the firm borrows $200,000 for one year is closest to 11.5 percent. 15 percent. 26.5 percent. 13.53 percent