A bank issues a loan to be repaid by level end-of-year payments for ten years at an annual effective interest rate of 10%. The bank invests these payments at an annual effective interest rate of 10% for the first four years and 7% for the next six years. Calculate the bank's annual effective yield rate on this loan over the ten-year period. (A) 7.90% (B) 8.20% (C) 8.33% (D) 8.67% (E) 9.10%