PrepTest 138, Section 4, Question 17
Humankind would not have survived, as it clearly(50 more words not shown)
Which one of the following(11 more words not shown)
- AStudents do not(36 more words not shown)
- BOrganisms are capable(36 more words not shown)
- CIf fragile ecosystems(26 more words not shown)
- DThe natural resources(33 more words not shown)
- EPublic buildings do(36 more words not shown)
Reading the argument
Take the survival requirement seriously. We're told humankind would not have survived without ancestors willing to sacrifice themselves for close relatives. Humankind did survive. On those premises, that willingness must have existed. And because the passage classifies that sacrifice as altruism, at least some altruism must have existed too.
We don't need to claim every ancestor was completely selfless. Nor do we need to decide whether this account of human history is actually correct. The parallel question asks us to match the reasoning once the premises are accepted.
What we’re looking for
Here's the chain in ordinary language: the observed result required one thing; that thing in turn involves a further quality; therefore the further quality was present. Survival required the willingness to sacrifice, and that willingness was altruistic. Look for an answer that gives us the result as a fact, then follows its requirements to the final conclusion.
Working the answers
- ACorrect
Raising grades takes the role of human survival. More study time takes the role of willingness to sacrifice. Good time management takes the role of altruism. The answer says higher grades require more studying, and more studying requires good time management.
We are then told some students did raise their grades. Those students must have studied more and therefore must have managed their time well. Just as observed survival establishes the required altruism, observed grade improvement establishes the required time management.
- B
Not consuming other organisms is enough to establish an ability to manufacture carbohydrates. But consuming other organisms doesn't establish an inability to manufacture them. A plant could conceivably obtain carbohydrates both ways. This incorrectly treats the two routes as mutually exclusive; it doesn't follow requirements backward from an observed result as our argument does.
- C
This says endemic species will perish without protection and explains why their confinement to one ecosystem makes them vulnerable. It doesn't add that the species have in fact survived, then use that fact to establish protection and a further required quality. The observed-result step and the second link in our chain are missing.
- D
This predicts resource depletion from failure to replace materials, then raises another depletion problem associated with the extra power replacement generally requires. It doesn't start with an outcome known to have occurred and establish the requirements that must therefore have been met. The qualified 'generally' connection also differs from the firm links in the original.
- E
This is the closest structural distraction: harmony requires good design, and good design requires expensive construction. But we're never told that any public buildings actually harmonize with their surroundings. The conclusion instead gives two alternatives: they are expensive or they fail to harmonize. To match the original, we would need observed harmony followed by a conclusion that the required expense was incurred.
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