Use the Information for the Question(s) Below

Use the information for the question(s) below.
Shepard Industries expects free cash flow of $10 million each year. Shepard's corporate tax rate is 35%, and its unlevered cost of equity is 10%. The firm also has outstanding debt of $40 million and it expects to maintain amount of debt permanently.
-Assume that the corporate tax rate is 40%,the personal tax rate on income from equity is 20% the personal rate on interest income is 36%.The effective tax advantage of a corporate issuing debt would be closest to:

A) 10%
B) 15%
C) 25%
D) 28%