A Firm Has a Profit Margin of 15 Percent on Sales

A firm has a profit margin of 15 percent on sales of R20,000,000.If the firm has debt of R7,500,000, total assets of R22,500,000, and an after-tax interest cost on total debt of 5 percent, what is the firm's ROA?

A) 8.4%
B) 10.9%
C) 12.0%
D) 13.3%
E) 15.1%