Typically, the longer a beverage has been in use in a particular place, the more widely that
Why this is right
This adds some plausibility to the link the author was assuming between "used more widely in Paraguay" and "originated in Paraguay". It is similar to (A), in the sense that it's connecting one of the two premises (more varieties / more widely used) to the idea of how long it's been in use. However, (A) used Absolute language: if you have a great number of varieties of X, then you've probably had X for a long time. This kind of language could apply to a lot of South American countries in the same way, and thus it wouldn't help us give the edge to Paraguay. (E) uses Relative language: if X is more widely used, then you've had X for longer. The relative language matches what he heard in the premise, and because of the Volume Dial nature of the answer, it's suggesting that if Paraguay is #1 when it comes to widely used then it's #1 when it comes to how long mate has been in use. The country where mate has been in use the longest is presumably where mate originated, so the more we make Paraguay sound like the country where mate has been in use the longest, the more we're strengthening the conclusion. This answer does not definitively establish that Paraguay is the place where mate has been used the longest (the connection described is only what's typically true), but this answer still does more than any other answer to add some plausibility. ** Only keep reading for nerdy Volume Dial discussion ** A lot of us are bothered by the fact that the Volume Dial relationship in this answer is written backwards. These relationships are invertible but not reversible: the higher the volume setting, the louder the music the lower the volume setting, the softer the music But going backwards seems dicey. Just because the music got louder doesn't mean that someone raised the volume setting. Maybe they just moved the speaker closer to my ear. Maybe there was a towel covering up the speaker and they removed it. This answer would be much stronger if it were written: the more widely used something is, the longer it's been somewhere But a conditional or a volume dial relationship can still add some plausibility, even if it's in "backwards" form. Say we have a theory that Erika has a crush on Mark. She's been looking at her phone a lot, waiting for a text from him. (naturally there could be other explanations for why she's compulsively looking to see if he's texted) However, hearing "When Erika has a crush on somebody, the anxiously awaits texts from them" still adds some plausibility to our theory, even though structurally it's in an 'illegal' form of "If Conclusion, then Premise". In the world of Strengthen and Weaken, we're not dealing with perfectly proving (or refuting) conclusions. It's more about plausibility and innuendo. If a theory predicts X and X is true, that doesn't automatically mean the theory is right, but it strengthens the credibility of that theory. The author has the theory that mate originated in Paraguay (i.e. that it's been in use there the longest). This answer assigns a prediction to that theory: if it's been in Paraguay the longest, then we'd expect to find it more widely used there than anywhere else. Since that matches our observation, it strengthens the author's theory.
Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.