A $500,000 loan was to be repaid over 15 years with level end-of-month payments. The interest rate was 10% per year, convertible monthly. After the 48th payment, the loan was refinanced at a nominal rate of i per year, convertible monthly. The length of the loan was unchanged, but the new end-of-month payments were each $473.98 lower than the original payments. Find i.| (a) 7.4% (b) 7.7% (c) 8.0% (d) 8.3% (e) 8.6%