@tams2018903 As we see in the correct answer, D, the passage is analyzing psychological and economic studies to see how they apply to questions of international relations. A is really narrow; the researchers are looking at more than jus the motives involved in certain types of decision making during conflict. It's a general study of loss aversion and risk taking being applied to politics. The word "collective" is also inaccurate because these are individual decisions we are studying, not decisions that people are making as a group.