A Toronto firm wants to maintain a growth rate of 8% without incurring any additional equity financing. The firm maintains a constant debt-to-equity ratio of 0.5, a total asset turnover ratio of 0.83 , and a profit margin of 8%. What must the retention ratio be? O a. 75.1% O b. 72.7% O c. 71.8% O d. 74.4% O e. 76.3%