Catherine has been receiving a monthly annuity payment from a life annuity with a 20 year guarantee which she purchased at age 70 . Catherine's sister, Norma, was named the beneficiary after Catherine's husband died several years ago. Norma died last year and Catherine died this year at age 91. To whom will the remaining annuity payment be made? Select one: a. Norma's estate b. No annuity payment is payable c. Catherine's children d. Catherine's estate