Which of the following statements is CORRECT?

Question $6$ options:

a$)$

The ratio of long$-$term debt to total capital is more likely to experience seasonal fluctuations than is either the DSO or the inventory turnover ratio.

b$)$

An increase in a firm's debt ratio, with no changes in its sales or operating costs, could be expected to lower the profit margin.

c$)$

If two firms have the same ROA, the firm with the most debt can be expected to have the lower ROE.

d$)$

An increase in the DSO, other things held constant, could be expected to increase the total assets turnover ratio.

e$)$

An increase in the DSO, other things held constant, could be expected to increase the ROE.