Natalia went to the general manager to file a complaint regarding something her supervisor said that implied she would be demoted or fired if she did not submit to a sexual request. Which step should the general manager take when investigating this complaint?

Take help of neutral third party for investigating for sexual harassment claims.

Explanation:

Sexual harassment claims and case at work place and organization occurs wen any mistreatment , offerings, task, etc is based on sexual terms .Employee can be treated of getting fired or adverse effect if they do not fulfill or cooperate such sexual favors in work environment, which is illegal act and punishable crime.

According to the question,for investigation of sexual harassment activity, manager should hire a neutral third party for investigation. Claim for asking sexual favors by treating demotion can get clarified in this way.  

answer; face validity;

answer; promote the individual as a "progressive being";