Susan receives an annuity in the form of a gift on her eighteenth birthday. The annuity will make level payments of $500 on her nineteenth birthday through to her thirty-fifth birthday. Starting on her 36th birthday and continuing forever, she will receive $1000. Find the value of the annuity on Susan's eighteenth birthday, assuming the annual effective rate of interest is 4.2%. A. 18,071.52 B.17,343.11 C. 18,568.40 D. 17,819.96