The DuPont equation shows that a firm's return on equity (ROE) is determined by three factors: net profit margin, total asset turnover, the return on assets (ROA). operating profit margin, return on assets (ROA), and the total assets turnover. net profit margin, total asset turnover, and the equity multiplier. return on assets (ROA), total assets turnover, and the equity multiplier.

a. net profit margin, total asset turnover, the return on assets (ROA).

b. operating profit margin, return on assets (ROA), and the total assets turnover.

c. net profit margin, total asset turnover, and the equity multiplier.

d. return on assets (ROA), total assets turnover, and the equity multiplier.