The designation of a trustee of a testamentary trust as beneficiary to receive the return of the accumulated contributions in a lump sum, a lump-sum death benefit including take-home-pay reserve, if any, the lump sum option pursuant to section 5014.2(a) of this Title, the commuted value of a five or ten year guarantee option pursuant to section 5014.2(b) of this Title, or a lump- sum alternative option pursuant to section 5014.2(c) of this Title shall be proper if the following conditions are met:
"Trustee (or trustees) of the testamentary trust established by my last will."
N.Y. Comp. Codes R. & Regs. Tit. 21 § 5013.2