PrepTest 155, Section 4, Question 18
Certain changes in North American residential architecture after(43 more words not shown)
Which one of the following,(7 more words not shown)
- AHigh ceilings and(17 more words not shown)
- BThin-walled, low-ceilinged houses(11 more words not shown)
- CHouses with low(18 more words not shown)
- DThin walls allow(13 more words not shown)
- ESoon after World(11 more words not shown)
Reading the argument
Air-conditioning could let builders stop relying on some older ways of keeping houses cool. That story makes sense. But making sense isn't the same as establishing the main cause of a change.
The passage says that houses without the traditional high ceilings and thick walls sold well when they had air-conditioning. Perhaps buyers liked the new designs. Perhaps the houses were cheaper or felt cozier. We know the houses sold well; we haven't yet established why builders changed the architecture.
It's easy to read this as a collection of historical facts and move on. Then the question asks us to weaken the argument. That's a signal to pause and find the claim being supported.
The key is in the first sentence: the architectural changes are attributed mainly to greater availability and affordability of air-conditioning. That causal explanation is what we need to challenge. We don't have to deny that the houses existed or sold well.
What we’re looking for
What if improved building materials made the designs practical? What if economic changes altered what people could afford or wanted to buy? Those are possible competing explanations, not new historical facts. I'd look for an answer showing that something besides air-conditioning better accounts for the change.
Working the answers
- A
This gives another advantage of the old designs: high ceilings and thick walls withstand severe weather. But the question concerns why builders moved away from those features. An advantage of keeping them doesn't establish that air-conditioning failed to play the main role in allowing the change. Builders could give up one benefit to obtain another.
- B
Higher heating costs are a drawback of thin walls and low ceilings. That doesn't explain why builders adopted them or show that air-conditioning wasn't the main factor. A design can become popular despite a cost. We need evidence against the proposed explanation, not merely another item on the new design's list of disadvantages.
- CCorrect
These designs were prevalent even in places with no demand for residential air-conditioning. Why would air-conditioning be the main explanation for adopting a style in places where people didn't want it? This comparison gives us a reason to look for another factor capable of producing the architectural pattern.
Notice that the answer says where there was no demand, not before air-conditioning existed. Its force comes from the geographical comparison: the designs are common even without the demand that would make the proposed explanation compelling. We don't need to invent a historical sequence to see the problem.
- D
Losing cooled air through thin walls makes cooling less efficient. But that's another drawback, not an explanation of what drove the architectural change. Air-conditioning could still be the reason builders found the new designs practical even if thick walls would have retained the cooled air better.
- E
This is tempting because it resembles our prediction. New insulation might help explain why a builder could use different walls without sacrificing comfort. That gives us a possible alternative to investigate.
But E only says the technology was widely applied. It doesn't establish that insulation, rather than air-conditioning, was mainly responsible for the architectural changes. The technologies could have worked together: air-conditioning could make the change practical while insulation helped the system work efficiently. The author said mainly, not exclusively.
Compare that with C. C places the architectural pattern in areas without demand for the proposed explanation. E adds another technology that could coexist with that explanation. It leaves the main-cause claim more intact, making C the stronger challenge.
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