PT158 S4 Q13 ExplanationMedical researcher: A new screening

Answer choices, explained

1. A

   Out of Scope8% picked this

   A surgical operation that is dangerous is ethically justified only for treating a medical condition

   This answer introduces a general ethical principle about when dangerous surgery is justified — namely, that it should only be performed for conditions more dangerous than the surgery itself. But the argument does not depend on any such sweeping principle. The argument's reasoning is narrower: it moves from "some polyps are nonmalignant" to "some surgeries are unnecessary." The assumption needed is a factual claim about nonmalignant polyps specifically, not a broad ethical standard governing all surgery. Apply the negation test: if we deny this principle (dangerous surgery can sometimes be justified even without a more dangerous condition), the argument about unnecessary polyp surgery still stands on its own terms.

   8%
2. B

   Correct64% picked this

   Surgical removal of nonmalignant polyps detected by the new screening test is not

   Why this is right

   The argument concludes that the test leads to unnecessary dangerous surgeries because some removed polyps are nonmalignant. This reasoning requires the assumption that removing nonmalignant polyps is not always medically necessary. Without this assumption, the argument collapses: if every nonmalignant polyp removal were medically justified — because nonmalignant polyps cause blockages, carry future cancer risk, or create other medical complications — then no surgery would be truly "unnecessary," and the conclusion would fail. Apply the negation test: "Removal of nonmalignant polyps IS always medically necessary." If that were true, every polyp removal prompted by the test would be justified, and the conclusion that some surgeries are unnecessary becomes impossible. The negation destroys the argument, confirming this is a necessary assumption. Note the careful wording: "not always" means "at least sometimes unnecessary" — an appropriately modest claim for a necessary assumption.

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

   64%
3. C

   Out of Scope7% picked this

   If the new screening test encourages medically unnecessary operations, then probably it either should not be used or

   The argument concludes that the test leads to some unnecessary surgeries — a limited critique identifying a drawback. It does not conclude that the test should be abandoned entirely. A medical test can have downsides (some unnecessary procedures) while still being valuable overall (catching genuinely malignant polyps). The argument does not need the stronger assumption that the test should not be used. Apply the negation test: if we deny this (the test should continue to be used), the argument's conclusion that some surgeries are unnecessary still holds perfectly well.

   7%
4. D

   Wrong Category5% picked this

   A polyp detected by the new screening test should be surgically removed if

   This answer addresses malignant polyps — the uncontroversial side of the issue. Nobody disputes that cancerous polyps should be removed. The argument's gap concerns nonmalignant polyps and whether their removal is always necessary. Affirming that malignant polyps need surgery does nothing to bridge the gap between "nonmalignant" and "unnecessary removal." It is answering a question the argument is not asking.

   5%
5. E

   Too Strong16% picked this

   The screening test is medically useful only when it detects a polyp

   This answer claims the test is useful "only when" it detects polyps requiring treatment. The argument does not need such a restrictive assumption about the test's overall utility. The test could be useful for many purposes — monitoring, early detection, research — while still leading to some unnecessary surgeries. The argument's narrow conclusion is about unnecessary procedures, not about the test's entire value proposition. The "only when" language creates a condition far stronger than what the argument requires. The necessary assumption is simply that some nonmalignant polyp removals are medically unjustified — not that the test has limited usefulness.

   16%