Arnold, a highly competent employee, had been overlooked for a promotion twice in a span of six months. He recently filed a claim for discrimination with the EEOC. Ever since he has filed the discrimination suit, he has been facing hostility at the workplace. His schedules have been changed without any notification and he has received an unfair performance review from his superiors. This is an example of $\_\_\_\_\_.$

Group of answer choices

reverse discrimination

sex discrimination

bona fide occupational qualification

reasonable accommodation

retaliation