A recent study showed that the immune

Answer choices

1. A

   Too Strong: all16% picked this

   All of the participants in the study drank either tea or coffee, and

   It's not necessary that within the study, people only drank tea or only drank coffee. It's possible they also had subjects who drank neither and subjects who drank both. When you quote a correlation from a study, for example "Patients who had remdesivir along with a nasal flush recovered breathing function sooner than did patients who only had the remdesivir", that correlation you're naming isn't providing an exhaustive list of all the categories of research subjects. A correlation can cherry-pick certain subsets of the research population in order to highlight an interesting relationship. That doesn't mean those two subsets were the only two subpopulations of subjects. This answer feels tempting, but only as an inference we think we're pulling from the correlation we got in the premise. This answer doesn't have anything to do with the move from the Evidence to the Conclusion, so we also want our test savvy to kick in and remind us that, "This answer isn't ruling out an alternate cause, and it's not saying something that's crucial to the author's causal explanation being plausible."

   16%
2. B

   Too Strong: no10% picked this

   Coffee has no health benefits that are as valuable as the boost that tea purportedly gives to

   This argument is only looking at one potential health benefit that tea has. It's not ruling out the idea that coffee may also have some health benefits of its own.

   10%
3. C

   Correct57% picked this

   In the study, drinking coffee did not cause the blood cell response

   Why this is right

   Whenever we're doing Necessary Assumption and we see an answer choice that's ruling out an idea with "not / no" language, we get enticed (many, many correct answers take this form). These are the easiest and most important types of answers to consider negating. Would it hurt the author's argument if we said, "Yo, author --- drinking coffee caused the blood cell response time to double"? Yes, it would, because that would provide an Alternate Explanation for the curious fact. Alternate Explanations are the #1 way to weaken causal arguments (a.k.a. Explain Curious Fact arguments). Why do the blood cells of tea drinkers take half the time that blood cells of coffee drinkers take? The author's explanation is that, "Clearly, tea is doing something great; it cuts your response time in half!" This alternate explanation is saying, "Maybe, tea is doing nothing, and it's just that coffee does something not-great, that doubles your response time." Imagine that a normal blood response rate is 2 seconds (for people who drink neither tea nor coffee). In this study, tea drinkers' blood took half the time of coffee drinkers' blood. The author is picturing this: normal / coffee tea 2 secs 1 sec This answer, when negated, is saying this: normal / tea coffee 2 secs 4 sec In both cases, the response time of tea is half that of coffee. The author assumed tea was doing something good to cause this asymmetry, which means the author must assume that "it's not the case that coffee just did something bad to cause this asymmetry".

   Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

   57%
4. D

   Not Necessary9% picked this

   Coffee drinkers in general are no more likely to exercise and eat healthily than

   If we negate this, it's saying that "coffee drinkers are more likely to exercise and eat healthily than are tea drinkers". Would that weaken? Would that provide an alternate explanation for why the immune system response time from tea drinkers is superior? No, that's moving in the opposite direction. If coffee drinkers are generally more healthy than tea drinkers, and yet in this study we still saw that tea drinkers have way faster immune response, that would actually strengthen the author's notion that tea is doing something amazing for our immune systems. This answer could have been correct if it had said, Coffee drinkers in general are not significantly less likely ...

   9%
5. E

   Too Strong: any8% picked this

   Coffee and tea do not have in common any chemicals that fight disease in

   The author doesn't need for coffee and tea to be 100% chemically distinct. They might both have antioxidants, for example. That doesn't hurt the author's argument. It's possible that tea has more immune system value than coffee because of the quantity of its helpful chemicals. Like, they could share all the same disease-fighting chemicals, but if tea carries five times as much of those chemicals per serving as does coffee, then the author's causal story still makes sense.

   8%