Sapp Trucking's balance sheet shows a total of noncallable $$60$ million long$-$term debt with a coupon rate of $7\mathrm{.}00\%$ and a yield to maturity of $6\mathrm{.}00\%.$ This debt currently has a market value of $$75$ million. The balance sheet also shows that the company has $10$ million shares of common stock, and the book value of the common equity $($common stock plus retained earnings$)$ is $$100$ million. The current stock price is $$17\mathrm{.}50$ per share; stockholders' required return, rs$,$ is $14\mathrm{.}00\%$; and the firm's tax rate is $25\%.$ The CFO thinks the WACC should be based on market value weights, but the president thinks book weights are more appropriate. What is the difference between these two WACCs?

a$.0\mathrm{.}60\%$

b$.0\mathrm{.}71\%$

c$.0\mathrm{.}45\%$

d$.0\mathrm{.}34\%$