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Set 4: Inferences (Advanced)

Explanation

Answer: D

PASSAGE

The double-blind clinical trial—where neither patients nor doctors know who receives treatment—is considered the gold standard for establishing medical efficacy. Critics note, however, that many successful treatments have obvious side effects that 'unblind' the study, potentially introducing placebo effects that inflate measured benefits.

What limitation of experimental methodology does the passage identify?

A. Double-blind trials are never used in medicine.
B. Side effects never reveal which group receives treatment.
C. Placebo effects cannot affect trial outcomes.
D. Practical features of interventions can compromise the controlled conditions that define rigorous study design.✓ Correct

Detailed Explanation

This question asks you to draw a logical conclusion from the text. Obvious side effects 'unblind' the study = practical features compromise control. A valid inference must be supported by evidence in the passage, even if not stated directly. Look for clues in the text that strongly suggest the answer. Avoid conclusions that require assumptions beyond what's written. Valid inferences are strongly supported by multiple pieces of evidence in the text. Be cautious of choices that go too far beyond what the passage actually states. The best inference is the one most directly supported by textual evidence.

Key Evidence:

• "obvious side effects that 'unblind' the study"

Why others are wrong: A (They are the 'gold standard.'), B (Side effects do unblind.), C (Placebo effects 'inflate measured benefits.').