请教费费逻辑第8题

8. The stable functioning of a society depends upon the relatively long-term stability of the goals of its citizens. This is clear from the fact that unless the majority of individuals have a predictable and enduring set of aspirations, it will be impossible for a legislature to craft laws that will augment the satisfaction of the citizenry, and it should be obvious that a society is stable only if its laws tend to increase the happiness of its citizens.

The claim that a society is stable only if its laws tend to increase the happiness of its citizens plays which one of the following roles in the argument?

(A) It is the conclusion of the argument.
(B) It helps to support the conclusion of the argument.
(C) It is a claim that must be refuted if the conclusion is to be established.
(D) It is a consequence of the argument.
(E) It is used to illustrate the general principle that the argument presupposes

为什么选的不是D呢?

哪位牛人帮忙解答一下,谢谢!

通篇都在支持和解释第一句话:

一个社会的稳定决定于市民的目标的长期稳定.这样一个结论很明显地可以从如下事实中看出来:除非人们的主体有一个可预见的长期的目标(A),否则立法机构将不可能制定令市民满意的法律(B);同时只有当法律可以增加市民们的满意度(B)时一个社会才能稳定(C).(申明，不是直译,是意译)

这么一段翻译看来,文中的推理结构就是说:UNLESS A,B; ONLY IF B, C.

B→A,C→B然后可以推出C→A,也就是说一个社会要稳定一定要有可预见的长期目标.

恰好是第一句话的结论吧?

希望我解释清楚了.