Hi Etsevdos,
I like the fact that you are working in the 90's RC. It's my personal opinion that you really get a great workout with this RC passage because you are being asked a more difficult type of question. Think of this as heavy lifting, increasing your strength so that you can easily do the weights on test day. So well done and keep it up.
But let's move on to your question. First let's address why (A) is correct. We are introduced to the concept of morality in the opening lines, the author speaks generally about that morality connecting it to "public good" in line 9. Throughout the rest of the passage that connection is reinforced. The last two sentences of the passage could be summarized (or combined) as
CEO moral
not take action that detracts from public good
I agree that you diagrammed the first part of Answer Choice (A) correctly with:
right
contribution to public good
The contrapositive of which looks like:
contribution to public good right
Note that it is not "wrong," it 's just "not right."
So Answer Choice (A) does a pretty good job of encapsulation of that logic that starts with the penultimate sentence.
But let's look at (E) because this is where you may have gotten so focused on your diagramming that you forgot what was stated in the passage. I agree that your initial diagramming of (E) looks good (great job with the "unless" statement by the way) but can you spot where you went wrong in the contrapositive? I am asking not because it's going to get you to the right answer necessarily but because you need to make sure you have the skill down on test day.
So what is wrong with (E)? It's addressing "others," that is to say other people. As an example of public good, the author discusses the paper mill hypothetical in lines 42-47. Reread that. Is any person being harmed in that example? Or is it just a forest and a lake? That's the problem with (E). You have connected "public good" to just "others" but public good means people, forests, lakes etc. That's why (E) is incorrect and a bit of a Shell Game answer.
Thanks for the great question and I hope this helped.