Of the Following, Which Is the Most Plausible Explanation for Why

Of the following, which is the most plausible explanation for why women continue to earn less than men?

A) Women have fewer years of experience than men.
B) Women are not as motivated to be successful at work; they would rather be at home.
C) Women in the workforce, by choice or because of discrimination, are concentrated in lower-paying jobs.
D) Employers intentionally set lower pay rates in jobs filled mostly by women than in different jobs filled mostly by men.