Logical ReasoningDifficulty: Hard

PT123 S2 Q15 Explanation

A new government policy

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

TopicsSufficient Assumption

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Stimulus

A new government policy has been developed to avoid many serious cases of influenza. This goal will be accomplished by the annual vaccination of high-risk individuals: everyone 65 and older as well as anyone with a chronic disease that might cause them to experience complications from the influenza virus. Each year’s vaccination all high-risk individuals to receive a vaccine for a different strain of the virus.

What this question is testing

Sufficient Assumption

Your task

Find the assumption that, if added, guarantees the conclusion follows.

Common trap

Answers that only partly bridge the gap, leaving the conclusion unproven.

Winning move

Identify the new term in the conclusion and pick the choice that links it to the evidence.

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

The question
15.

Which one of the following is an assumption that would allow the conclusion above to

Answer choices

  1. Irrelevant Comparison4% picked this

    The number of individuals in the high-risk group for influenza will not significantly change from

    The number of individuals in the high-risk group does not impact whether those individuals will need to receive a vaccine.

  2. Weakens (if anything)3% picked this

    The likelihood that a serious influenza epidemic will occur varies from

    This makes it possible that one year there is no risk of influenza and so high-risk individuals may not need to receive a vaccine that year.

  3. Reiterates Premise / No Impact30% picked this

    No vaccine for the influenza virus protects against more than one strain

    This tells us something we already know. We were told that "Each year’s vaccination will protect only against the strain of the influenza virus deemed most likely to be prevalent that year", so we already know that the vaccine only protects against one strain. This doesn't resolve our concern that if the same strain is the most prevalent for two consecutive years, then a high-risk patient wouldn't necessarily need to get a new vaccine each year.

  4. Correct62% picked this

    Each year the strain of influenza virus deemed most likely to be prevalent will be one that had not previously been deemed

    Why this is right

    This ensures that each year the strain of influenza virus deemed most likely to be prevalent is one that has not been vaccinated against previously.

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

  5. Out of Scope1% picked this

    Each year’s vaccine will have fewer side effects than the vaccine of the previous year since the technology for

    Side effects are not relevant to this argument.

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