Which of the following may be true of the cost of debt and cost of equity?

a: the weighted average cost of capital is the computed by assigning weights to the cost of the debt and cost of equity of a firm

b: the cost of debt for a firm is always equal to the cost of equity to the firm.

c: the cost of internally generated equity for a firm is greater than the cost of externally generated equity funds for the firm.

d: the cost of internally generated equity for a fir is less than the cost of debt for the firm

e: the cost of externally generated equity is the sum of the cost of debt and the cost of retained earnings