David just finished compiling his firm’s retained earnings statement for the month ended May 31. What should he do with the figure he calculates at the bottom of this statement? A : He should include this amount in his calculation of revenues on the firm’s income statement. B : He should include this amount in his calculation of assets on the firm’s balance sheet. C : He should include this amount in his calculation of expenses on the firm’s income statement. D : He should include this amount in his calculation of stockholders’ equity on the firm’s balance sheet.