(d) It is unlawful:
1. For an employer to discriminate against any employee or applicant for employment;
2. For an employment agency to discriminate against any individual; or
3. For a labor organization to discriminate against any member or applicant for membership,
because such employee, applicant for employment, individual, member, or applicant for membership has opposed any practice made unlawful by this section or because the employee, applicant for employment, individual, member, or applicant for membership has made a charge, testified, assisted, or participated in any manner in an investigation, a proceeding, or litigation under this act.