Explanation
Correct answer: D.
Choice D is the best answer. The archeologist bases their claim on the fact that the hyena bone features unevenly spaced parallel notches. But if unevenly spaced parallel lines were found on "decorative art" at another Neanderthal site, it would suggest that the hyena bone is probably decorative art as well—not a counting tool.
Why the other choices are wrong
Choice A
Choice A is incorrect. This choice doesn’t weaken the underlined claim. If anything, it might actually strengthen the claim: assuming we can make an inference about Neanderthals using a fact about early humans, it provides more support for the idea that the person who made the notches was counting something.
Choice B
Choice B is incorrect. This choice doesn’t weaken the underlined claim. The fact that another artifact had parallel notches made with a different stone tool doesn’t tell us anything about the use of either artifact. For all we know, they could both have been used for counting.
Choice C
Choice C is incorrect. This choice doesn’t weaken the underlined claim. The fact that it took effort to make the lines doesn’t tell us anything about what the lines were for.