Answer b

@sajaalami94, This is a necessary assumption question. One way to identify a necessary assumption is to negate it and see if the argument falls apart. (B) has no impact on Inez's argument because even if we negate (B) - countries can both be strong and moral, one could still conclude that the countries should be judged by the morality of its actions, not by strength. If we negate (C) on the other hand, and it is impossible to assign moral weight to countries' actions, one can no longer judge a country by the morality of its actions because there is no standard of morality.

I am confused about the question stem! I thought this question was a weakening type question instead of NA. Can someone please explain how "presupposition that underlies Inez' argument?" refers to strengthening with necessary assumption?

Hi Ashkan, A presupposition is a weird synonym for an assumption. So, the stem is really asking us "which assumption underlines the argument" which, while still a weird construction, is asking us which assumption is foundational to or necessary for the argument. This is a very old question (1992), and the more modern ones tend to phrase the question stems a bit more clearly.