At year-end on December 31, 2013, both Firm X and Firm Y report a return on assets (ROA) equal to 6%. However, Firm X reports a greater return on equity (ROE) than Firm Y. Which of the following must be true? O a. Firm X has a greater return on sales than Firm Y O b. Firm X has a lower return on sales than Firm Y Oc. Firm X has a lower leverage ratio than Firm Y o d. Firm X has a greater leverage ratio than Firm Y O e. None of the above is correct