Hi I need help with the interpretation and explanation for each letters. Thank You!

5-23 EVALUATING LUMP SUMS AND ANNUITIES Wang Yun just won the lottery, and she must choose among three award options. She can elect to receive a lump sum today of $61 million, to receive 10 end-of-year payments of $9.5 million, or to receive 30 end-of-year payments of $5.5 million. a. If she thinks she can earn 7% annually, which should she choose? b. If she expects to earn 8% annually, which is the best choice? c. If she expects to earn 9% annually, which option would you recommend? d. Explain how interest rates influence her choice