Which of the Following Are Factors That Help Explain Why

Which of the following are factors that help explain why the percentage of U.S. industrial firms paying dividends has increased since the early 2000s? I. decrease in the number of non-dividend paying firms
II) maturing of young, successful firms
III) signaling of a firm's financial health
IV) May 2003 tax act

A) I and III only
B) II and IV only
C) I, II, and III only
D) II, III, and IV only
E) I, II, III, and IV