PT143 · S3 · Q19 A recent study showed that the immune

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."

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.

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 ...

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.