took me 10 minutes but I got it right. My only worry is on timed practice how will I answer this in 2:19 minutes if I will diagram the whole thing?

There was a floating premise in this stimulus—specifically the one about acetylsalicylic acid slowing the deterioration associated with Alzheimer’s. This premise is not connected to the author’s conclusion. In a strengthen question, the correct answer will often connect this “floating” premise to the conclusion, and that is exactly what answer choice B does. I hope this helps you see the correct answer differently.

@OwenTrela I totally understand where you're at. My primary goal after reading a strengthening stem is to ask: how can I find an answer choice that helps make the conclusion of the author more true? If any AC makes the conclusion or explanation of the author less true or doesn't remotely help it, I do not pick it and move on to the next. So in practice, here I looked at answer choice A: Some plants can develop resistance to air pollution, well thats not good for trying to prove that air pollution eradicates plant diseases. B) Talking about infection by the disease, but I am concerned with air pollution eradicating said diseases, so no. C) Weakning the argument by saying scientists actually dont know what effects air polution has on some plant species. D) This one is saying the two diseases came back after the city became less polluted, and that grants support to the explanation that air pollution is what caused both diseases to be eradicted thats my winner. E) Neither helps nor weakens my argument, it is just saying the two diseases were the only ones that dissapeard doesnt say how. That was the way i thought through the answer choices and ive always kept the conclusion/explanation of the author in the back of my mind while actively combing through the answer choices looking for one to make said conclusion more likely/true.

@LSAT1011 It is when you see two or more facts in a stimulus and assume something that isn’t stated. For example: “Conan is the best detective, yet his clearance rate is below average.” These two statements may seem confusing at first. How can Conan be the best detective if his clearance rate is low? This confusion comes from operating under a naive assumption—that if Conan is the best detective, his clearance rate must also be the highest. That assumption is what creates the apparent contradiction in your mind. The correct answer resolves this by breaking that assumption: “Conan gets the hardest cases.” Now it makes sense why Conan could have a below-average clearance rate. Hope that helps.

@FultonHoover Same