Here we have a strengthen with necessary premise question. Remember that a premise is necessary for a conclusion if the falsity of the premise guarantees or brings about the falsity of the conclusion. First we check to see if the answer choice strengthens the passage, and then, if it does strengthen, we negate the answer choice to see if its negation makes the argument fall apart. If the answer choice does both those things then it is our correct answer.
Conclusion: "a nation that owes money to another nation cannot be a world leader."
Why? Nations are just like individuals in that the lender sets the terms of its dealings with the borrower.
What's the issue here? We are making a conclusion about what constitutes not being able to be a world leader, when we have never discussed this at all. We need to somehow connect our premise to something that gives us guidelines about being able to be a world leader or not.
Answer choice (C): "A nation that has the terms of its dealings with another nation set by that nation cannot be a world leader."
Does this answer choice strengthen the argument? Yes.
Answer choice (C) helps us connect to the premise to make our conclusion. If a nation that has the terms of its dealings with another nation set by that nation cannot be a world leader, then we know that a nation that owes money to another nation cannot be a world leader since a nation that is a lender sets the terms of its dealings with a nation that is a borrower, i.e. a nation that owes money to another nation.
Negation: "A nation that has the terms of its dealings with another nation set by that nation can be a world leader."
Does the negation make the argument fall apart? Yes.
If the negation is true, then it no longer stands that a nation that owes money to another nation cannot be a world leader since a borrower nation, i.e. a nation that owes money to another nation, can still be a world leader.
If you have any specific questions about the other answer choices, please feel free to clarify.
Hope that clears things up! Please let us know if you have nay other questions.
