On May 1, 2016, Plotter, Inc., issued $30,000 of ten-year, 12% bonds payable dated January 1, 2016. The cash received amounted to $29,808. The bonds pay interest semiannually. Potter's fiscal year ends on June 30, 2016. What amount of interest expense should be reported on the income statement prepared on June 30, 2016, assuming straight-line amortization?

a. $603.20 b. $669.60 c. $549.60 d. $609.60