; (ii) such that, to the extent practicable, the percentage of the Climate Choice Stock Index Fund that is invested in each stock is the same as the percentage determined by dividing the aggregate market value of all shares of that stock by the aggregate market value of all shares of all stocks included in the index selected under subparagraph (A); and (iii) to ensure that no investment in the portfolio is an investment with respect to a fossil fuel entity. . 4. Government Accountability Office report (a) Definition In this section, the term fossil fuel entity has the meaning given the term in section 8438(a) of title 5, United States Code, as amended by this Act. (b) Report Not later than 1 year after the date of enactment of this Act, the Comptroller General of the United States shall submit to Congress a report that— (1) analyzes, as of that date of enactment— (A) the proportion of the stocks, bonds, and other obligations held by the Thrift Savings Fund that are stocks, bonds, or other obligations of a fossil fuel entity; and (B) the effect on individuals holding accounts in the Thrift Savings Fund of the Thrift Savings Fund holding stocks, bonds, or other obligations of fossil fuel entities under the climate policies that would be needed to limit global temperature increase to 2 degrees Celsius, given technology that is available and economically feasible as of that date of enactment; and (2) provides a plan and mechanism that would allow the Federal Retirement Thrift Investment Board to divest from fossil fuel entities to prevent or mitigate any negative investment risk on individuals holding accounts in the Thrift Savings Fund.