Cartwright Communications is considering making a change to its capital structure to reduce its cost of capital and increase firm value. Right now, Cartwright has a capital structure that consists of $20\%$ debt and $80\%$ equity, based on market values. $($Its D$/$S ratio is $0\mathrm{.}25.)$ The risk$-$free rate is $6\%$ and the market risk premium, rM $$ rRF$,$ is $5\%.$ Currently the company's cost of equity, which is based on the CAPM, is $12\%$ and its tax rate is $25\%.$ What would be Cartwright's estimated cost of equity if it were to change its capital structure to $50\%$ debt and $50\%$ equity?

Group of answer choices

$13\mathrm{.}00\%$

$13\mathrm{.}65\%$

$14\mathrm{.}84\%$

$15\mathrm{.}58\%$

$16\mathrm{.}00\%$