Art Rutter sold an apartment building in May 2018 for a small amount of cash and a note payable with payments beginning in 2019. Principal and interest payments are due annually on the note in April of 2019 through 2023. Art died in August 2018. He willed all his assets to his daughter Amelia. Art's gross estate is about $16 million, and his estate tax deductions are very small. What tax issues should the executor of his estate consider with respect to reporting the sale of the building and the collection of the installments?