Six months before her death, Debra sent checks equal to the amount of the gift tax annual exclusion to Adrian, Bruce, and Claire. None of the checks had been presented for payment before Debra's death. See Metzger v. Commissioner.

Questions: 

a. Are the checks included in Debra's gross estate?

b. What if Adrian, Bruce, and Claire had deposited the checks in their respective bank accounts two days before Debra's death but the checks had not cleared Debra's bank before her death?

c. Except that Debra had sent the checks ten days before her death?