PrepTest 104, Section 1, Question 19
Pollen and other allergens can cause cells in(51 more words not shown)
If the statements above are(10 more words not shown)
- APollen and other(5 more words not shown)
- BColds are more(5 more words not shown)
- CAntihistamines, when taken(8 more words not shown)
- DThe sleeplessness that(9 more words not shown)
- EAny effect antihistamines(15 more words not shown)
Reading the argument
The allergy treatment blocks a chemical that colds don't use. My first reaction is that the same treatment shouldn't carry over to cold symptoms.
For allergies, the passage gives a clear chain: allergens can trigger histamine, histamine causes the nasal symptoms, and antihistamines block its action. Then the last sentence removes histamine from the process by which colds produce symptoms. The allergy explanation therefore doesn't carry straight over to colds.
There is another detail to keep in mind: antihistamines can also make someone drowsy. That effect doesn't disappear just because we're discussing a cold rather than an allergy. I can see why the drug might still affect the person, even though the stated allergy mechanism doesn't address the cold.
What we’re looking for
We're asked what must be true. I'll test my initial reaction against the exact limits of the information.
Working the answers
- A
The passage explains a process by which allergens cause allergy symptoms. It does not provide a complete account of what causes colds. Ruling histamine out of the cold-symptom process doesn't establish that pollen or another allergen couldn't have some different role. We cannot import outside knowledge about cold causes.
- B
Knowing that the stated allergy mechanism doesn't address colds gives us no overall comparison of treatment difficulty. Other treatments might work well for colds. The passage doesn't compare the full set of available treatments for either condition.
- C
This is the tempting extension of my initial thought, but it goes too far. Consider the drowsiness: what if it led someone to rest, and that rest happened to help the congestion? We haven't established that this would happen. The point is that the passage hasn't ruled out that indirect possibility. If it occurred, the antihistamine could help even though blocking histamine wasn't responsible.
More fundamentally, the passage says antihistamines have other effects, including drowsiness—not that drowsiness is their only other effect. Nothing rules out some other effect that could help with cold-related congestion.
We don't have to prove that such an effect exists. Because the question asks what must be true, a possibility the passage leaves open is enough to defeat the claim of complete ineffectiveness. “This mechanism won't help” doesn't establish “this drug cannot help in any way.”
- D
Making someone drowsy doesn't establish that the drug effectively treats sleeplessness associated with allergies. The effect might be insufficient, or the sleeplessness might persist despite it. D adds a treatment-success claim the passage doesn't give us.
- ECorrect
This stays with the mechanism the passage rules out. If antihistamines reduce cold symptoms, that reduction cannot come from blocking histamine, because histamine plays no role in producing those symptoms.
Unlike C, E leaves other possible effects open. It neither guarantees that the drug helps nor declares it completely ineffective. It tells us which explanation of any benefit is unavailable, which is exactly what the stated facts establish.
More Must Be True questions
Learn the LSAT our way
Our platform drills Must Be True questions at your level and adjusts as you improve.