Three Months After Brianna Timkin Died, Her Executor Received the Final

Three months after Brianna Timkin died, her executor received the final $40,000 installment from a sale of land that Brianna completed several years ago. Which of the following statements is true?

A) The $40,000 is both included in Brianna's gross estate and subject to tax on her estate's income tax return.
B) The $40,000 is subject to neither income nor estate tax, because it was received after Brianna's death.
C) The $40,000 is only subject to tax on her estate's income tax return.
D) The $40,000 is included only in Brianna's gross estate.