This question is confusing to me. Answer choice D is correct but I feel that it doesn't actually present the primary purpose.
I agree with the first part of choice D: "criticize one school of thought's definition of a certain concept" but I don't see how the second part "by providing examples that illustrate the implications..." is completely relevant.
The author does use two examples (ozone in paragraph 1 and the communities in paragraph 2 and 3), but is the author really using these examples, with their corresponding implications, as his form of criticism?
He seems to more that he is using them as examples to illustrate the sides of the conflict and elaborate on them.
From POE, I was left with A, B, and D. I crossed off D for the reason above, crossed off B because the author does more than just "summaries and illustrate," and very hesitantly chose A, despite that I felt it was too strong (although the examples do show some potentially detrimental effects...but it doesn't seem like it's a "conflict").
Any help or thoughts would be greatly appreciated for why D is wrong, and what else makes A, B wrong.
Thanks