A loan of $ 50,000 is repaid with annual payments at the end of each year for 20 years. Each of the first 19 payments is equal to two times the amount of interest then due. The final payment repays the remaining loan balance at that time. Interest is charged at an annual effective rate of 7%. Calculate the amount of the final loan payment. (A) $ 13, 475.03 (B)$ 14,931.90 (C) $ 15,319.72 (D) $ 16,541.01 (E) $ 17,892.33