Archaeologist: A skeleton of a North American mastodon that became ext

OFFICIAL EXPLANATION

The stimulus sets up an interesting argument that appears fairly reasonable. A mastodon skeleton has been found containing a human-made projectile dissimilar to those of the part of Eurasia closest to North America and because Eurasians did not settle in North America until shortly before the peak of the Ice Age, the first Eurasian settlers of North America probably came from a more distant part of Eurasia than the area nearest North America. To make a very rough analogy using dialects, it is like a resident of Washington, D.C. saying, “The visitors we just met did not sound like they were from Virginia, so they must be from a much more distant part of the U.S.” Reading that rough analogy, you can see that the speaker has assumed that the visitors are from the U.S. Of course, that does not have to be the case—they could be from England or France or elsewhere. The same form of assumption has occurred in the argument, and the author has assumed that the projectile is of Eurasian origin.

Answer choice (A): This is the correct answer. This answer hurts the argument by indicating that the projectile is apparently not Eurasian, suggesting that the first Eurasian settlers could have come from any part of Eurasia, including the area closest to North America.

Answer choice (B): This is the most attractive wrong answer, but regardless, this answer does not hurt the argument. Some students attempt to conclude that since the people were nomadic, they could have moved to areas farther away and found projectiles like the one in the mastodon. However, even though these individuals remained nomadic, they were apparently nomadic within the area of Eurasia closest to North America because the answer clearly states, “The people who occupied the Eurasia area closest to North America...” Hence, they did not necessarily occupy other areas and this answer does not hurt the argument.

Answer choice (C): This Opposite answer supports the argument by showing that the projectile in the mastodon was not a one-time, anomalous occurrence. If other, similar projectiles come to light, then the author’s position would be strengthened.

Answer choice (D): This Opposite answer supports the argument by connecting other artifacts of the same age as the projectile to parts of Eurasia more distant than the area of Eurasia closest to North America. This adds further evidence to the idea that the first Eurasian settlers of North America probably came from a more distant part of Eurasia than the area nearest North America.

Answer choice (E): This Opposite answer supports the argument by indicating that the part of Eurasia closest to North America may not have been inhabited just before the Ice Age. If this area was uninhabitable, then it is more likely that settlers coming to North America came from more distant regions.