In the case of an estate or trust (other then a trust meeting the specifications of subpart B), there shall be allowed as a deduction in computing its taxable income (in lieu of the deduction allowed by section
170
(a), relating to deduction for charitable, etc., contributions and gifts) any amount of the gross income, without limitation, which pursuant to the terms of the governing instrument is, during the taxable year, paid for a purpose specified in section
170
(c) (determined without regard to section
170
(c)(2)(A)). If a charitable contribution is paid after the close of such taxable year and on or before the last day of the year following the close of such taxable year, then the trustee or administrator may elect to treat such contribution as paid during such taxable year. The election shall be made at such time and in such manner as the Secretary prescribes by regulations.