A quick approximation of the typical firm's cost of equity may be calculated by
a) adding a 5 percent risk premium to the firm's before-tax cost of debt.
b) adding a 5 percent risk premium to the firm's after-tax cost of debt.
c) subtracting a 5 percent risk discount from the firm's before-tax cost of debt.
d) subtracting a 5 percent risk discount from the firm's after-tax cost of debt.