Logical ReasoningDifficulty: Easy

PT111 S4 Q10 Explanation

A recent study suggests that Alzheimer’s

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsStrengthen

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Stimulus

A recent study suggests that Alzheimer’s disease, which attacks the human brain, may be caused by a virus. In the study, blood from 11 volunteers, each of whom had the disease, was injected into rats. The rats eventually exhibited symptoms of another degenerative neurological disorder, Creutzfeldt-Jakob disease, which is caused by a to conclude that Alzheimer’s disease might be caused by a virus.

What this question is testing

Strengthen

Your task

Find the choice that makes the argument's conclusion more likely to be true.

Common trap

Answers that are consistent with the argument but add no real support, or that strengthen a claim the argument doesn't make.

Winning move

Locate the gap between evidence and conclusion, then pick the choice that closes it.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
10.

Which one of the following statements, if true, would most strengthen the scientist’s hypothesis that Alzheimer’s disease is

Answer choices

  1. No Impact1% picked this

    Alzheimer’s disease in rats is not caused by

    Knowing that Alzheimer's disease in rats is not caused by a virus doesn't address the hypothesis about Alzheimer's in humans. This statement does not strengthen the link between Alzheimer's in humans and a viral cause.

  2. No Impact1% picked this

    Creutzfeldt-Jakob disease affects only motor nerves in rats’ limbs, not

    While this choice gives us information about Creutzfeldt-Jakob disease, it does not directly connect or impact the viral hypothesis concerning Alzheimer's disease. It doesn't suggest any link between the virus and Alzheimer's.

  3. No Impact2% picked this

    The virus that causes Creutzfeldt-Jakob disease in rats has no effect

    The virus causing Creutzfeldt-Jakob disease having no effect on humans doesn't strengthen the claim about Alzheimer's disease and a viral cause. It's an extraneous detail that doesn't connect Alzheimer's directly to a viral origin.

  4. Correct94% picked this

    The symptoms known, respectively, as Creutzfeldt-Jakob disease and Alzheimer’s disease are different manifestations of

    Why this is right

    If Creutzfeldt-Jakob disease and Alzheimer's disease are different manifestations of the same disease, this strongly suggests a shared cause, potentially a viral one. This supports the hypothesis that Alzheimer's could be caused by a virus, much like Creutzfeldt-Jakob.

    Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.

  5. No Impact2% picked this

    Blood from rats with Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into

    This answer choice doesn't strengthen the hypothesis about Alzheimer's having a viral cause. Whether blood from infected rats fails to infect other rats does not confirm a viral link between Alzheimer's and Creutzfeldt-Jakob diseases.

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