Naturalist: For decades we have known that the tuatara, a New Zealand

I am responding to a pm from getgyan. Does anyone know the source of this question?

Here is my analysis:
Sentence #1 --- tuatara on south island dying
Sentence #2 --- if they're all one species, the same as the north island ones, then saving the south island tuatara is not important
Sentence #3 --- new research: south island tuatara are their own species
Sentence #4 --- since they are unique species, saving the south island tuatara is important

Very interesting --- with the change in species classification, saving the south island tuatara went from unimportant to important. That is key for this argument.

Which one of the following principles most helps to justify the naturalists’ argumentation?
(A) In order to maximize the number of living things on Earth, steps should be taken to preserve all local populations of animals.
First of all, does the phrase "number of living things on Earth" refer to number of species or number of individual living entities? Biologist do try to save species that are going extinct, but I don't think anyone is trying to maximize the total number of individual living things. That's crazy. I believe scientist don't even know the total number of species on earth: they can estimate it, but the value of that number is somewhat unrelated to their main task. Savings species is not a numbers game: biologists regard each species as something valuable in and of itself: no one has the idea that, somewhere out there, we are keeping notches for each species on Earth. More to the point, if we were trying to maximize number of living things, then we would be trying to save the south island tuatara, regardless of their species classification: this in no way explains the huge change in prioritization that appears in the argument. This is not correct.

(B) When an animal is in danger of dying, there is an obligation to help save its life, if doing so would not interfere with the health or well-being of other animals or people.
First of all, this is about an individual animal, not a species. More importantly, if this were true, then there would have been this obligation to save them in the first sentence, even when we thought the north and south islands tuataras were all the same species. This also doesn't explain at all how the deaths of the south island tuatara went from unimportant to important. This is not correct.

(C) The threat of local extinction imposes no obligation to try to prevent that extinction, whereas the threat of global extinction does impose such an obligation.
This is interesting. Local extinction --- there are tuataras everywhere, and only those on the south island are dying --- no obligation = it is not important to save them. But, global extinction --- the south island tuataras are the only example in the world of that particular species ----- obligation = it is important to save them. This very cogently follows and explains the shift in the argument. This is a promising choice.

(D) Human activities that either intentionally or unintentionally threaten the survival of an animal species ought to be curtailed.
This is a distractor. The south island tuataras are dying because of their natural predators. The argument says zilch about human activity having an impact on the south island tuataras. Yes, it is true that human activity often is a culprit in species extinction, so that's a common assumption to make. Nevertheless, it's not mentioned at all in this particular passage, so there's no support for this answer. This is incorrect.

(E) Species that are found in only one circumscribed geographical region ought to be given more care and attention than are other species because they are more vulnerable to extinction.
A wild claim, totally unsupported by the passage. All over the world, there are species that happen to exist "in only one circumscribed geographical region" --- they are not all teetering on the verge of extinction. Every species that is found "in only one circumscribed geographical region" --- we are easily talking about millions of plants, animals, bacteria, protists, etc. etc. We can't make a sweeping generalization about all of them, especially one so extreme as saying they are all "vulnerable to extinction." Tell that to the specialized bacterial species that are found only in the Ganges River and that absolutely thrive there! This answer choice a completely over-the-top claim. This is incorrect.

Thus, we can easily eliminate four answers, and we are left with only one. (C) makes a distinction that precisely mirrors the distinction made in the argument, so it powerfully supports it. (C) is the OA.

Does all this make sense?

Mike