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Ok so I've been sitting here trying to tackle this question but I was wondering if someone could explain why the answer is E. According to Kaplan it says that the other choices are possible but choice E is definitive. The question I have is, when working through this problem and coming across the answer choices that are possible, why would assume they're also not definitive. In other words, why should I have picked choice E, even though answers ABCD may also fit the criteria.

Any help is appreciated.

BTW i forgot to mention this is on sec. 2