Why Should the Debt Portion of the WACC Be Adjusted

Multiple Choice

Why should the debt portion of the WACC be adjusted for tax?

A) Because the interest paid on debt is not taxable at the firm level
B) Because the interest paid on debt is not taxable at the investor level
C) Because all components of the WACC are not taxable
D) Because the principle paid on the debt is not taxable at the firm level