Everything Else Equal, in Which of the Following Situations Will

Multiple Choice

Everything else equal, in which of the following situations will a firm's degree of operating leverage (DOL) increase? Assume the firm currently generates a positive net operating income. 

A) Sales increase substantially.
B) The firm issues preferred stock.
C) Fixed costs are decreased.
D) The firm takes advantage of quantity discounts for the first time.
E) The firm's sales move closer to its operating breakeven point.