PrepTest 107, Section 4, Question 24
Medical researcher: As expected, records covering the last(74 more words not shown)
Which one of the following,(8 more words not shown)
- AThe hospital records(20 more words not shown)
- BMothers giving birth(21 more words not shown)
- CThe hospital records(14 more words not shown)
- DSome babies not(12 more words not shown)
- EWomen who receive(20 more words not shown)
Reading the argument
Maybe the mothers receiving better prenatal care also had advantages beyond that care.
For example, greater resources might give someone access to both prenatal care and better nutrition. If nutrition helps explain the baby's birth weight, the association with care would not by itself establish how much the care did. That is a possibility to investigate, not a claim that the medical care has no benefit.
The records show two relationships. Premature babies are more likely to have low birth weights and health problems. Mothers with adequate prenatal care are less likely to have low-birth-weight babies. The researcher turns the second relationship into a causal conclusion: adequate care significantly reduces the risk.
What we’re looking for
I would look for another explanation of that relationship. Nutrition or some other advantage could be one. If an outside advantage explains the difference in birth weights, the observed relationship would not establish the care as its cause. That is the direction I would initially look for in a weakening answer.
Working the answers
- A
Many normal-birth-weight babies can be born after inadequate care even if adequate care significantly reduces risk. The conclusion concerns a difference in likelihood, not a guarantee. Without a comparison of the rates, these successful outcomes do not show that the proposed benefit is absent.
- BCorrect
This takes a different route from the nutrition prediction: the records may create the association through the way hospitals assign the care labels.
Suppose a mother received adequate care, but the hospital lacks the record of it. If she gives birth prematurely, the hospital routinely labels her care inadequate. Premature babies are already more likely to have low birth weights. This classification can put many mothers of low-birth-weight babies into the inadequate-care group even without evidence that their care really was inadequate. The hospital is using the premature birth to assign the label.
The researcher treats that label as evidence of care received before the birth. B shows it can instead be assigned because of how the birth turned out. That weakens the inference from these records without requiring us to prove prenatal care is ineffective.
- C
This concerns the label for prematurity, not the label for prenatal care. It could make us question how the records relate low birth weight to premature birth. But it does not explain why mothers recorded as receiving adequate care had fewer low-birth-weight babies. B targets that care comparison; C targets a different relationship.
- D
Some low-birth-weight babies after adequate care are compatible with a significant reduction in risk. The claim never says adequate care prevents every such birth. D also expressly concerns babies not born prematurely, so we should not misread it as an example of adequate care failing to prevent prematurity.
- E
This gives the argument support. Adequate care is associated with fewer premature births, and the passage already connects prematurity with low birth weight. That suggests a possible way the care could reduce low-birth-weight risk. It does not prove the causal claim, but it points toward the researcher's explanation rather than undermining it.
More Weaken questions
Learn the LSAT our way
Our platform drills Weaken questions at your level and adjusts as you improve.