A firm has $4,000,000$ shares of common stock outstanding, each with a market price of $$12\mathrm{.}00$ per share. It has $25,000$ bonds outstanding, each selling for $$980.$ The bonds mature in $20$ years, have a coupon rate of $9$ percent, and pay coupons semi$-$annually. The firm's equity has a beta of $1\mathrm{.}5,$ and the expected market return is $15$ percent. The tax rate is $30$ percent and the WACC is $15$ percent. What is the risk$-$free rate?

Multiple Choice

$6\mathrm{.}28$ percent

$8\mathrm{.}00$ percent

$19\mathrm{.}36$ percent

$9\mathrm{.}22$ percent