Logical Reasoning

PT5 · S1 · Q9 It is not known whether bovine spongiform

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It is not known whether bovine spongiform encephalopathy (BSE), a disease of cattle invariably deadly to them, can be transmitted directly from one infected animal to another at all stages of the infection.

Setup

BSE is invariably fatal to cattle. It is not known whether an infected animal can pass it directly to another at every stage of the infection.

Conditional (if) Direct transmission at → there is now a reservoir of all stages is possible infected cattle incubating disease

No diagnostic test can identify an infected animal before it shows overt symptoms.

The Blank (therefore)

If such direct transmission occurs, the disease cannot be eradicated by _______.

Evaluate

We have a conditional rule and the conclusion begins by triggering it.

We live in a world where direct transmission occurs, which means we live in a world where there is currently a bunch of cattle infected with BSE but not yet showing symptoms.

We have no way to test them until they start showing overt symptoms. So ... we're kinda screwed?

Goal

The blank is supposed to name a method that wouldn't effectively get rid of the disease. The only method that would work is to just kill all cattle. Otherwise, we're pretty screwed. We don't know how to find all the infected cattle since many of them are currently hosting the disease but asymptomatic.

So let's stay flexible and just ask ourselves with each answer whether it's a method that would / wouldn't work to eradicate the disease.

9.

Which one of the following best completes the argument?

  1. Correct

    Removing from the herd and

    Why this is right

    This is saying, "once it shows symptoms, we'll remove it and kill it". But that won't get rid of the disease. There are currently cattle that have the disease but aren't showing symptoms. If we just killed the ones with symptoms, we wouldn't have killed all the ones that have the disease, so we would not have eradicated the disease.

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

    73% picked this

  2. Developing a drug that kills

    Opposite

    This sounds like it would work as a solution, since it treats all cattle. If we give them ALL a drug that kills the disease, then any cows that have the disease will no longer have it, and we will have eradicated it.

    5% picked this

  3. Destroying all cattle in areas

    Opposite

    Again, this would seemingly work because it deals with all cattle. If you kill ALL the cows in BSE areas, then you're eradicating BSE from those areas. And if you only raise cattle in areas where you know BSE hasn't ever been, you should be good to go with those cows.

    6% picked this

  4. Developing a vaccine that confers

    Opposite

    This would seemingly work since it's being done to all cattle. Every cow, going forward, will have lifelong immunity to BSE. All the ones that currently have and die from BSE will be the last cattle to suffer. Once they're all dead, the disease is functionally eradicated because the vaccinated generation of cattle will never get the disease.

    2% picked this

  5. Developing a diagnostic test that

    Opposite

    This would work because it would allow us to actually know which cattle have the disease. If we separate out all the ones that currently have it and kill them, then all the remaining cattle are BSE free. This test apparently would be able to tell whether a cow had BSE, regardless of whether it currently had symptoms or was still at the early incubation stage.

    14% picked this

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