Logical Reasoning

PT131 · S1 · Q22 Last summer, after a number

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Last summer, after a number of people got sick from eating locally caught anchovies, the coastal city of San Martin advised against eating such anchovies.

Apparent Paradox

Last summer, after a number of people got sick from eating locally caught anchovies, the coastal city of San Martin advised against eating such anchovies.

The anchovies were apparently tainted with domoic acid, a harmful neurotoxin.

However, a dramatic drop in the population of P. australis plankton to numbers more normal for local coastal waters indicates that it is once again safe to eat locally caught anchovies.

Evaluate

What changed? The answer should connect the drop in P. australis plankton to the assertion that it is now safe to eat anchovies.

22.

Which one of the following, if true, would most help to explain why it is now safe to lift the advisory?

  1. P. australis is one of

    Deepens the Paradox

    This makes it less understandable why it is safe to each anchovies again, because it creates additional varieties of plankton that can make anchovies toxic. The statements only provide that the population of P. australis returned to normal levels.

    7% picked this

  2. Correct

    P. australis naturally produces domoic

    Why this is right

    This relationship is consistent with T → PL the people of San Marin getting sick from eating locally caught anchovies, and given that the population of P. australis plankton has declined to normal levels, this addition of this rule supports the assertion that it is safe again to each anchovies. And by contrapositive, if the ~PL → ~T population of P. australis is not large, they do not produce enough domoic acid to make anchovies toxic.

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

    78% picked this

  3. Scientists have used P. australis

    Too Weak

    If P. australis is connected with domoic acid, it’s unclear that it’s safe to eat anchovies because the P. australis is still present in the area near San Martin. The population of P. australis returned to normal, but it was not eliminated. So there are still P. australis producing domoic acid that could make people sick. This does not reduce the threat to the point that anchovies are now safe.

    1% picked this

  4. A sharp decline in the

    Out of Scope

    Whether the anchovy population is large or small should not necessarily impact whether it is safe to eat those anchovies.

    2% picked this

  5. P. australis cannot survive in

    Reversal / Too Weak

    This says that if there is not ~SDA → ~SLN significant amounts of domoic acid, then P. australis cannot surve in large numbers. Knowing that P. australis did not survive in large numbers does not support the point that there is not significant domoic acid. Furthermore, that there is not significant domoic acid in the seawater does not show that the anchovies are safe.

    12% picked this

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