It took me a while to understand this one, hopefully this is helpful in your understanding.

1. Identify pronouns: "this" and "it" play a big role in this particular question.

2. Reread the question and replace the pronouns with what they are refering to. You may want to say "The fact that ..." then add the rest of the sentence.

This is not an argument setting out to prove that animals are not able to refer to concrete objects or abstract ideas.

It is an argument about the fact that: Animals signaling with each other (1st sentence) is not good enough evidence/does not prove that animals possess language.

So, AC (C) is not necessary because animals could refer to concrete objects or abstract ideas and it wouldn't break the argument! Even if we know for a fact that animals do refer to objects and ideas, that is not a fact confirmed by the first sentence which states the general understanding that they can signal.

AC (D) is focusing on the right stuff, the argument is concerned with the fact that "animals can certainly signal..." does not prove that "animals possess language".

(D) in other words says:

Signals that don't refer to objects or ideas are not a language.

negation:

signals that don't refer to objects or ideas are a langage

If the negation is the case then the first sentence would be good enough evidence to prove that animals possess language!

I tried to make this shorter but this was the best I could do lol hope this helps!

Edit: I wrote contrapositive instead of negation

was so hype when i predicted d as an answer choice and so devestated when it was explained as incorrect

@hajmcl95 My read of this section is that the authors inclusion of that whole paragraph (“In fact, there are are only…”) is not meant to be read as a valid conclusion to the prior claims. Rather, it is being used to emphasize that the point the flaw is making is so obviously incorrect (claiming that NYP violinists are not exceptionally good).

@LastLivingLily0 Its all about if you can keep track of the symbols. For example, I did 40—>/S - I was able to keep track of this because one mentioned 40 and the other mentioned skiing. If you can keep track of it without using more words I would imagine that would be more helpful. However, if you need more words to remember each condition, don’t hesitate to use as many words as you need. It is all about how you personally work best.

@Aubrey.Raile To my understanding, no. The contrapositive functions exactly the same so writing the original or contrapositive first shouldn’t matter.

It may be important if the question is specifically asking you to identify the contrapositive or vice versa, but otherwise they are exactlly the same.

@kittenWhiskers They want us to differentiate the predicate-verb from its modifiers. We know that “to kill” is modifying “fail.”

Consider how changing the sentence changes the predicate - Antibiotics HURT the bacteria that live in deep wounds - Antibiotics (subject) HURT (verb) bacteria (object). Only by removing the modifier “to kill” does “the bacteria" into an object. It doesn’t make sense if you are a normal person trying to derive the meaning of the sentence, but that is not what it is about, it is more of a puzzle with one logically correct answer.

So to sum it up, make note of verbs modifiying the main verb, and try to look at each passage as a puzzle.