Im having trouble with this one. I see how C is correct, but I don't fully understand how it's more correct than E. They are both missing a portion of the rule. For C its doing it for the benefit of someone else (which is implied) and for E its the evidence of it being beneficial (which is shown in the last sentence, unless you want to argue that problems being resolved isn't beneficial). Does anyone have a good way to distinguish the right answer choice in timed conditions? I don't.

I chose E, but for a second was tempted with B. I ended up ruling B out because of D. Although the levels may have been lower prior to to 85, it doesn't mean they were sufficient to even lower the risk of airborne illness so we can't, for certain, say that the risk is now higher. Idk if that makes sense but that's how I got there.

I think the only real difficulty for me on this question was realizing I should diagram. As soon as I did I saw the flaw, unfortunately, I had already submitted the wrong answer, Lol. Anyhow, does anyone have any tips for identifying when to diagram reasoning flaw questions? Or should that just be the default?

couldn't you rule out A because it's talking about Sewage pollution when the passage only talks about nutrient rich sewage pollution?