Logical ReasoningDifficulty: Medium

PT102 S2 Q6 Explanation

One test to determine whether a

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

TopicsNecessary Assumption

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Stimulus

One test to determine whether a person has been infected with tuberculosis consists of injecting the person with proteins extracted from the tuberculosis bacterium. Once a person has been infected by a bacterium, the person’s immune system subsequently recognizes certain proteins present in that bacterium and attacks the bacterium. This recognition also in this manner to an injection with the tuberculosis proteins has been infected with tuberculosis.

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

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

The question
6.

Which one of the following is an assumption on which the physicians’

Answer choices

  1. Trap4% picked this

    All of the proteins present in disease-causing bacteria can be recognized by the

  2. Trap11% picked this

    Localized skin irritations are a characteristic symptom of tuberculosis in

  3. Correct77% picked this

    The ability of the proteins present in the tuberculosis bacterium to trigger the skin irritation is

    Why this is right

    Answer C is correct.

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

  4. Trap2% picked this

    Some people who have been injected with proteins extracted from the tuberculosis bacterium will contract tuberculosis as a

  5. Trap5% picked this

    The body’s immune system cannot recognize infectious bacteria unless there are sufficient quantities of the bacteria to cause

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