Which of the following annuities would be included in an annuitant's gross estate at death?

a. An annuity payable to the annuitant for life, then payable to a beneficiary.

b. A single life annuity for the decedent's life.

c. An annuity payable to a decedent for a period that ends before the decedent's death

d. An annuity payable for a five-year fixed term. The annuitant lives beyond the fixed term.