Passage Summary: McKinley says they cannot do a secret study because the drug's side effects will give it away; Engle snaps back that McKinley is unfairly assuming they already know how the drug will affect people.

Conclusion: McKinley is making an unwarranted assumption about the final results of the drug study.

Reasoning: Engle claims McKinley cannot conclude the study is impossible because that conclusion relies on knowing the study's outcome in advance.

Analysis: Engle's response reveals a fundamental misunderstanding of McKinley’s point. McKinley is discussing the 'process' of the study—specifically, that physical side effects will break the 'blind' nature of the experiment. Engle, however, interprets 'knowing the drug is being administered' as 'knowing the results of the efficacy test.' To identify Engle's misinterpretation, look for an answer that highlights this confusion between the observable side effects of the drug and the ultimate success or failure of the drug's intended purpose.