Builtrite Supply is considering selling bonds for a plant expansion. Currently, Builtrite believes that it could sell $12-$year maturity, $$1000$ par value, $73/8\%$ coupon bonds after flotation costs for $$1036.$ If Builtrite is in the $34\%$ marginal tax bracket, what is the after$-$tax cost for the bonds?$5\mathrm{.}71\%3\mathrm{.}77\%6\mathrm{.}91\%4\mathrm{.}56\%$