; and (B) a credit subsidy is the most efficient way to achieve such increase (on a borrower-by-borrower basis). (2) The final maturity of loans made or guaranteed under this section shall not exceed a period of 20 years, or the period of 50 percent of the useful life of any physical asset to be financed by the loan, whichever is less as determined by the Secretary. (3) The Secretary may not make a loan guarantee under this section, with respect to any borrower, in excess of 80 percent of any potential loss on the loan. (4) The Secretary may not make any loan or loan guarantee under this section if the loan will be subordinated— (A) to another debt contracted by the borrower; or (B) to any other claims against the borrower in the case of default. (5) The Secretary may not make any loan guarantee under this section unless the Secretary determines that— (A) the lender is responsible; and (B) adequate provision is made for servicing the loan on reasonable terms and protecting the financial interest of the United States. (6) The Secretary may not make any loan guarantee under this section if the income from the loan will be excluded from gross income for purposes of chapter 1 of the Internal Revenue Code of 1986. (7) The Secretary may not make any loan or loan guarantee under this section unless— (A) the loan and interest supplements on any loan guarantee will be at an interest rate that is set by reference to a benchmark interest rate on marketable Treasury securities with a similar maturity to the loan being made or guaranteed; and (B) the minimum interest rate on the loan— (i) will be no less than the estimated cost to the Government of making the loan plus 1 percent, with the goal of keeping the interest rate below the interest rate of a comparable and competitive private sector benchmark financial instrument