EFFECT OF TAX DEDUCTIONS, EXEMPTIONS, OR CREDITS.

(a) A deduction, exemption, or credit allowed by law in connection with the estate tax inures to a person interested in the estate as provided by this section.

(b) If the deduction, exemption, or credit is allowed because of the relationship of the person interested in the estate to the decedent, or because of the purpose of the gift, the deduction, exemption, or credit inures to the person having the relationship or receiving the gift, unless that person's interest in the estate is subject to a prior present interest that is not allowable as a deduction. The estate tax apportionable to the person having the present interest shall be paid from the corpus of the gift or the interest of the person having the relationship.

(c) A deduction for property of the estate that was previously taxed and a credit for gift taxes or death taxes of a foreign country that were paid by the decedent or the decedent's estate inure proportionally to all persons interested in the estate who are liable for a share of the estate tax.

(d) A credit for inheritance, succession, or estate taxes, or for similar taxes applicable to property or interests includable in the estate, inures to the persons interested in the estate who are chargeable with payment of a portion of those taxes to the extent that the credit proportionately reduces those taxes.