Explanation

Reading the question: we have a logical argument to complete. Although we intend to digest the argument, we will gloss over the technical terms at first. We have three species and then some opinion language at the phrases "might represent a single species" and "is considered tentative." First opinion: what we'll call the single-species theory. Second opinion: that of the biologist, the opinion that a wealth of articles is on the way in support of the single-species theory. Third opinion: that of the author of this paragraph, namely, that the wealth of articles will "lend no support" to the single-species theory. He's not exactly saying the theory is wrong; he's saying something closer to the fact that the wealth of articles will not be so valuable.

Creating a filter: given the third opinion, our crude prediction for the blank is something like, "the articles will be worthless." Maybe the single species theory is in vogue and insubstantial articles will be written about it.

Applying the filter: Choice (A) contradicts the prompt, since, if the claim about Skull 5 couldn't be supported by articles at all, then the status of the claim in question would be worse than "tentative." Choice (B) says the articles will improve the theory, so it's out. Choice (C), similarly, implies that the articles might be useful, so (C) is out. Choice (D) might match our prediction; these articles doesn't sound so useful. Choice (E) discusses earlier articles and is irrelevant. Everything is out except for (D). Choice (D) is not the most powerful argument imaginable, but it's logical: the new articles will not add credibility because they will be based on the same critical piece of evidence, Skull 5. Choice (D) would be better yet if it specified that the new articles would not analyze the skull in a substantially new way or otherwise advance the analysis of the skull, but that detail is not required. The correct answer is (D).