13. If a firm has a debt-equity ratio of 1.0, then its total debt ratio must be which one of the following? A. 0.0 B. 0.5 C. 1.0 D. 1.5 E 2.0 14. The Purple Martin has annual sales of $687,400, total debt of $210,000, total equity of $365,000, and a profit margin of 5.9 percent. What is the return on assets? A. 5.74 percent B.6.48 percent C. 7.05 percent D. 7.78 percent E. 9.79 percent