This is a tough one, and only about 1/3 of test takers answer this one correctly. I can say that a good portion of being able to navigate this question comes from knowing what inferences can be made, and looking for the answer that is by far most likely to result from these relationships. So, let's look at it and see what we can determine.
The first sentence is actually critical, and it's also a bit confusing. If you are a small country, or a country in the southern hemisphere, then you do NOT have a permanent seat on the council. Since that's a positive sufficient condition and a negative necessary condition, I just turn that into a double-arrow:
- Small country
or Permanent Seat
Country Southern Hem
When I did this problem, I actually used two double-not arrows (and wrote this in reverse order), but the graphics of this forum don't allow me to show that easily. If you put a term between Small Country and Country Southern Hem it would be an "or" as shown above because if you get either one, you don't have a permanent seat. If that doesn't make sense, ask me about it and I'll break it down further
Then, as you note, countries with a Permanent Seat are in favor of increased efforts and a greater role. I reduced that second term to simply "In Favor" but it doesn't really matter; yours works equally well:
- Small Country
or Permanent Seat In Favor
Country Southern Hem
At this point, we have enough for (E). Starting at In Favor, we can ride back across the arrow using "some," and then travel to "Country Southern Hem," tossing a negative onto that from the double-not arrow. So, effectively, my inference is that "In Favor some are not Country Southern Hem." That's what (E) says, and that's the answer.
The last sentence of the stimulus is notable because it tosses a new "some" relationship into the mix, and one that would attach to part of the "In Favor" statement. However, I automatically threw that out an didn't even analyze it. Why? Because the basic form of it can't produce an inference. Take a look at the following relationship:
- A B C
Can I draw an inference there? No, you can't because the arrow is pointing the "wrong" way in order to work with "some." The stimulus attempts to add a sort of ":some: C" portion to In Favor, and that can't work so I just went right past it. At that point I knew that "In Favor some are not Country Southern Hem" (or "In Favor some are not Small Country") had to be the answer, so I went looking for that.
That's a really quick, causal explanation, but I hope it helps. Please let me know. Thanks!