Ignoring Costs Associated with New Issues, What Is the Cost

Ignoring costs associated with new issues, what is the cost of retained earnings the same as?

A) The cost of debt, as creditors have first call on retained earnings at the company's termination.
B) The weighted average cost of all the company's sources of capital as the company is indifferent as to the use of retained earnings or other sources.
C) The return on total assets as this ratio is equal to the sum of retained earnings plus dividends divided by total assets.
D) The cost of shares as retained earnings represent the undistributed profits belonging to the common shareholders.
E) The return on capital employed as retained earnings represents the opportunity cost of investment.