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Break the argument into its conclusion and evidence, then do exactly what the question stem asks with that structure.
Answers that sound relevant to the topic but don't connect to the argument's actual reasoning.
Predict what a right answer must do, then test each choice against the conclusion-evidence gap.
Which one of the following, if true, most helps to explain why the horse population peaked 25,000 years ago and then rapidly declined?
The forest-dwelling ancestor of horses
We would need a lot more information to know how the size of the horses' ancestor would have any impact on this situation.
0% picked this
The only true wild horse
This indicates that grasslands can exist in cold areas, and that wild horses live in these cold grasslands. To some degree, it helps explain why the horse population was large during a cold period. But it doesn't explain the other half of the paradox. Why did the horse population decline during the warmer period that followed?
1% picked this
Some modern species that are
It's possible that some fact about zebras could help explain the paradox we're given. But this answer doesn't explain why horse populations peaked during a cold period and then declined during a warming period. The fact that grasslands exist in warm areas, and animals related to horses live in those grasslands, does the opposite of what we want, if anything. It's evidence that horses might have thrived during the warming period discussed in the stimulus.
1% picked this
During cold periods there are
Why this is right
It's normal to expect grass to grow when it's warm, not when it's cold, but this answer states that the opposite is actually true. This indicates that the grasslands where horses thrive were more common during the cold period 25,000 years ago and less common during the warm period that followed. Hence, the horse population declined during the warm period. It's helpful to note that the stimulus never said how cold it got 25,000 years ago. It's easy to envision an ice age, or at least a very wintery, snowy climate where grass is unlikely to grow, but we're never told it was actually that cold. The LSAT very frequently does this, tricking us into assuming something that wasn't actually stated.
Skill tested: Paradox · how this choice captures the argument's function is the move to repeat next time.
94% picked this
Several cycles of a cold
We already know that horse populations have gone through cycles during the past 2 million years. We know that there appears to be some connection between the most recent cycle and a shift from a cold period to a warmer one. If anything, this answer is just consistent with information that we've already been given. It doesn't help explain why the horse population peaked 25,000 years ago and then rapidly declined.
4% picked this
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