Which of the following statements is incorrect?

A) Group of answer choices The best method to use when estimating a firms discount rate is the weighted average cost of capital approach.

B) The yield to maturity (YTM) is used for cost of debt after adjusting for the tax deductibility of interest on debt.

C) The yield to maturity is the discount rate that makes the present value of coupon and principal payments equal to the price of the bond.

D) The cost of debt can be calculated using the perpetuity model for the present value of cash flows.

E) All the answers are correct except one.