Logical reasoning PrepTest 122 · Section 4 · Question 19

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Most forests are much smaller than they used to be and are dying
Some of these forests are the only place where some of the most endangered species live
Maintain full complement of plants/animals → Regular interventions by resource managers

Answer Anticipation:
The stimulus here presents a rather bleak picture of the world's forests. The vast majority are smaller than they used to be and are dying out—a statement which draws a comparison between the past and the present (and also discusses a trend into the future). It then establishes that some of them are the "last" refuge of certain endangered species, which suggests that once they're gone, so too will those species be gone.

Then, it concludes with a conditional statement. As the strongest statement in the stimulus, it's likely to factor into the correct answer. This conditional establishes that regular interventions by resource managers are a requirement for all the plants and animals in these forests to survive. The contrapositive of this statement establishes that if these resource managers don't intervene, then the forests won't maintain their full complement of plants and animals—in other words, some of them will die off.

Let's find an answer dealing with that last statement. If it brings in information from either of the first two, that's fine, as well, but our anticipation should focus on that last statement.

Answer Explanation:
The "great majority" of the world's forests are fragmented according to the first statement, so we can support an answer about most of the world's forests. And the conditional tells us that if resource managers don't regularly intervene in these forests, then some animals or plants will die. This answer is broader in stating that "if no one intervenes," but that guarantees that resource managers won't intervene, which in turn guarantees that some plants or animals in most of the world's forests (the fragmented ones, which make up over half) will die off. This answer is therefore supported by the stimulus and is correct.

Key Takeaway:
When a Must Be True stimulus features a mix of stronger and weaker statements, the stronger statements tend to be more directly connected to the correct answer. Focus on them in your anticipation and initial consideration of the answer choices.

Incorrect. The stimulus does establish that without the regular intervention of these resource managers some of the plants/animals in the fractured forests won't survive, but it doesn't specify which ones. The most endangered species could end up being saved by conservationists while others die because of the lack of resource manager intervention.

Incorrect. While the stimulus notes that the fragmented forests have lost the ability to sustain themselves, it only notes that they may lose some of their plant/animal species, not that they've already done so. So the loss of these plant/animal species can't trigger the loss of self-sustainability since the latter has already happened but the former has yet to.

Incorrect. The stimulus doesn't discuss fully functioning forest ecosystems, so this answer can't be supported. It's also pretty strong ("always"), which is generally a sign of an incorrect answer.

Incorrect. The discussion around resource managers is conditional—in other words, there's no indication that anything is actively happening with them. So this answer stating that they're already intervening can't be supported.