Which statement is true?

A.		If market weights can be calculated, we use market weights rather than book weights to calculate WACC.
B.		If we don't know the book weights of the various sources of capital in the capital mix, we cannot calculate the market weights either.
C.		The same WACC calculated for a company is used for all new projects regardless of their riskiness.
D.		Cost of debt goes up after it is adjusted for tax.