Use the following information to find the internal growth rate: Current sales: $6,000; Current costs: $3,000; Total Assets: $20,000; Total Debt: $8,000; Total equity: $12,000; Constant dividend payout ratio: 40%. Total assets and costs are proportional to sales. The level of debt and equity is independent of the level of sales. a. 7.93% b. 11.25% c. 6.38% d. 9.89% e. 5.88%