Sam Snider died February 14, 2015, survived by his spouse Janet and several children. Sam had not made any taxable gifts. Sam's gross estate was $7 million. In each of the following independent situations, indicate the amount of Sam's exemption equivalent that is portable to Janet and that can be used by Janet's estate if Sam's executor makes the appropriate election.

a. Sam's deductions, including the marital deduction, total $3.7 million; Janet dies in 2016.

b. Sam's deductions, including the marital deduction, total $1.1 million; Janet dies in 2016.

c. Sam's deductions, including the marital deduction, total $6 million; Janet dies in 2020.

d. Sam's deductions, including the marital deduction, total $5.5 million. Janet remarries late in 2015. Her new spouse dies early in 2016 with a $9 million taxable estate, and Janet dies late in 2016.