"Affirmative action is ethical because it has the effect of reducing discriminatory practices against large groups of people who have suffered in the past" is an example of reasoning based on which theory?

Affirmative Action isn't ethical. There is no real theory that justifies it.

Explanation:

I doubt that this reasoning is based on any rational theory. In the first place, you can't repay the sins of a past generation by placing burdens on a generation living presently. That simply requiring one group of people to suffer for what another group did. And, anyway, the theory doesn't work for white people. When whites suffer enslavement, as they have in the past, at the hands of Mongols, or at the hands of Arabs, then nobody raises the subject of Affirmative Action. In other words, whatever "theory" is being used, isn't being used consistently. And that means that the ostensible justification for Affirmative Action isn't the real reason that it is used.

true