10. A firm's assets have been consistently growing at a rate of 15% per year (i.e. the firm's internal growth rate is 15% ). The firm's retention ratio (also referred to as the reinvestment or plowback ratio, and denoted by the letter " b ") is 60%. If the firm's total asset turnover is 25%, what is the firm's profit margin? A. 0.24 B. 0.77 C. 0.87 D. 1.15 E. 1.30