An investor purchases one municipal bond and one corporate bond that pay rates of return of $9\%$ and $10\mathrm{.}5\%,$ respectively. If the investor is in the $20\%$ tax bracket, his after$-$tax rates of return on the municipal and corporate bonds would be$,$ respectively

Multiple Choice

$10\mathrm{.}80\%$ and $8\mathrm{.}40\%$

$9\%$ and $8\mathrm{.}40\%$

$9\%$ and $10\mathrm{.}5\%$

$7\mathrm{.}20\%$ and $10\mathrm{.}5\%$