; but for purposes of this section allowances under section 167, and allowances under section 611, shall be considered as expenditures. (e) Exploration expenditures This section shall not apply to any expenditure paid or incurred for the purpose of ascertaining the existence, location, extent, or quality of any deposit of ore or other mineral (including oil and gas). (f) Software development For purposes of this section, any amount paid or incurred in connection with the development of any software shall be treated as a research or experimental expenditure. (g) Only reasonable research expenditures eligible This section shall apply to a research or experimental expenditure only to the extent that the amount thereof is reasonable under the circumstances. (h) Coordination with research credit (1) In general Section 41(d)(1)(A) shall be applied by substituting expenses under section 174A for specified research or experimental expenditures under section 174 . (2) Denial of double benefit (A) In general Section 280C(c) shall not apply and the amount taken into account under this section as research or experimental expenditures shall be reduced by the amount of the credit allowable under section 41(a). (B) Election of reduced credit (i) In general In the case of any taxable year for which an election is made under this subparagraph— (I) subparagraph (A) shall not apply, and (II) the amount of the credit under section 41(a) shall be the amount determined under clause (ii). (ii) Amount of reduced credit The amount of credit determined under this clause for any taxable year shall be the amount equal to the excess of— (I) the amount of credit determined under section 41(a) without regard to this subparagraph, over (II) the product of the amount described in subclause (I), multiplied by the rate of tax under section 11(b). (iii) Election An election under this subparagraph for any taxable year shall be made not later than the time for filing the return of tax for such year (including extensions), shall be made on such