Smith and Sons Inc. has a target capital structure that calls for $40$ percent debt, $10$ percent preferred stock, and $50$ percent common equity. The firm's current after$-$tax cost of debt is $6$ percent, and it can sell as much debt as it wishes at this rate. The firm's cost of preferred stock is $11$ percent and its cost of retained earnings is $14$ percent. The firm expects to generate $$15,000$ in retained earnings this year. Compute the weighted average cost of capital $($WACC$)$ break point associated with issuing new common stock.

a$.$ $$37,500$

b$.$ $$30,000$

c$.$ $$15,000$

d$.$ $$17,500$

e$.$ $$150,000$