Great work, thank you for this.

Perfect example of an NA question where the AC doesn't need to be important, but does in fact need to be necessary in this case for the survival of the rhino species.

'Importance' is the only trick that the LSAT writers have for making a trap answer seem attractive, and a wrong answer unattractive for this type of question.

This is simply testing your valid argument forms and conditional chaining abilities. Assuming you've encountered the LG section, you could even think of this like an in/out game.

EW —> UR + UR —> INVD

EW —> PRC

or

A—>B—>C

A —> D

Now they simply run the Contrapositive on the chain getting: If not C, then not A (/C—>/A).

/A<—/B<—/C

D or /D (this lower rule now breaks away)

See how failing the Necessary condition (/C) by running the contrapositive makes us fail the Sufficient (/A). This means that, you either have both A and C, or neither of them in this case (Always together, never apart), which is why AC A is a contradiction because it tries to separate them (EW & INDV)

Further, as a result of running the contrapositive, you coincidentally fail the Sufficient condition (/A a.k.a. /EW) in its conditional relationship to (D a.k.a PRC), turning this once latter Necessary condition into a 'free floater.' This means that (based on which direction the chain is facing), you could in fact have EW & PRC together; or apart /EW & PRC; or neither of them /EW & /PRC. Ultimately, the fact that these two elements (EW & PRC) can in fact be separated from each other in this case demonstrates why AC D isn't a contradiction here.

Hope this helps see this question in a clearer light.

While I got this right timed and BR, I decided to come back and spend another 7 minutes on it to really understand why. I realized that this seems to make the most sense by POE and just using your intuition. Basically, since they were wrong for believing that agriculture started from scarce resources, the only other option you're left with is that, resources were needed in order for this practice of agriculture to be created. Looked at it in a kind of bi-conditional way.

This is a great reminder to never get complacent on this test. Keep going everyone, and remember too read carefully.