for the election under this section over the estate tax liability. For purposes of this clause, the term estate tax liability means the tax imposed by section 2001 reduced by the credits allowable against such tax. (3) Use in trade or business by family members A qualified heir shall not be treated as disposing of an interest described in subsection (e)(1)(A) by reason of ceasing to be engaged in a trade or business so long as the property to which such interest relates is used in a trade or business by any member of such individual’s family. (g) Security requirements for noncitizen qualified heirs (1) In general Except upon the application of subparagraph (F) of subsection (i)(3), if a qualified heir is not a citizen of the United States, any interest under this section passing to or acquired by such heir (including any interest held by such heir at a time described in subsection (f)(1)(C)) shall be treated as a qualified family-owned business interest only if the interest passes or is acquired (or is held) in a qualified trust. (2) Qualified trust The term qualified trust means a trust— (A) which is organized under, and governed by, the laws of the United States or a State, and (B) except as otherwise provided in regulations, with respect to which the trust instrument requires that at least 1 trustee of the trust be an individual citizen of the United States or a domestic corporation. (h) Agreement The agreement referred to in this subsection is a written agreement signed by each person in being who has an interest (whether or not in possession) in any property designated in such agreement consenting to the application of subsection (f) with respect to such property. (i) Other definitions and applicable rules For purposes of this section— (1) Qualified heir The term qualified heir — (A) has the meaning given to such term by section 2032A(e)(1), and (B) includes any active employee of the trade or business to which the qualified family-owned business interest relates if such employee has been employed by such