【单选题】Which of the following titles best describes the content of the passage as a whole?
A.
The Necessity for Earnings Differentials in Free Market Economy.
B.
Why Discrimination Against Employed Women by Government Employers and Private Employers Differs from Discrimination Against Self-Employed Women by Consumers.
C.
The Relative Effect of Discrimination by Government Employers, Private Employers, and Consumers on Women's Earnings.
D.
The Relative Effect of Private Employer Discrimination on Women's Earnings.