Which of the following titles best describes the content of the passage as a whole

A．Why Discrimination Against Employed Women by Government Employers and Private Employers Differs from Discrimination Against Self-Employed Women by Consumers
B．How Discrimination Affects Women's Choice of Type of Employment
C．The Relative Effect of Private Employer Discrimination on Men's Earnings as Compared to Women's Earnings.
D．The Relative Effect of Discrimination by Government Employers, Private Employers, and Consumers on Women's Earnings.