Concerning the Formula for the Federal Estate Tax

Concerning the formula for the Federal estate tax:

A) The tax base results after any post-1976 taxable gifts are added to the taxable estate.
B) The taxable estate is determined with reduction for any state death taxes paid.
C) Any income tax owed by the decedent can be deducted in arriving at the taxable estate.
D) Some unified transfer tax credit is available even if it has been fully utilized for lifetime gifts.
E) All of the above.