Which of the Following Is True About Employment Discrimination

Which of the following is true about employment discrimination?

A) Employers who discriminate against women will have lower costs than rival firms that hire employees strictly on the basis of merit (productivity) .
B) If employers can hire equally productive female employees at a lower wage than males, the profit motive gives them a strong incentive to do so.
C) The female/male earnings ratio is higher for persons who are married than for those who remain single.
D) Both a and c are true.