Hi nz,
A good prephrase will definitively eliminate answer choice C on this question. The ideal principle to strengthen any argument is one that ties the premises to the conclusion conditionally. But you have to make sure that the conditional connection "flows" in the right direction. It needs to be [Premises]
[Conclusion]. In other words, the premise information should be put into the sufficient condition, and the conclusion information should be put into the necessary condition.
Prephrasing in this question would give us this: If electing judges rather than appointing them would be likely to produce conflicts of interest, then judges should be appointed. Simplified: Likely Conflicts of Interest
Appointed.
Answer choice C reverses this: it puts the "appointing" in the sufficient condition, and the "conflicts of interest" in the necessary condition. It's the Mistaken Reversal of what we need (though even if you reversed the conditionality of C you'd still have some problems; which means it's actually AT BEST the Mistaken Reversal of what we need). The Mistaken Reversal principle will never be the best answer in these questions.
Answer choice E is much better because it matches the conditional flow we're looking for. The conditional structure of E (rephrased) is this: If a public office for which election campaigning would be likely to produce conflicts of interest, then it should NOT be changed from appointed to elected (meaning it should be appointed).
Simplified: Likely Conflicts of Interest
Appointed. That's our prephrase!
I hope this helps!
Jeremy Press
LSAT Instructor and law school admissions consultant
Follow me on Twitter at:
https://twitter.com/JeremyLSAT