Necessary AssumptionDiff: Hard
Logic Breakdown
Passage Summary: Selena argues an asteroid killed dinosaurs via a massive dust cloud. Trent disagrees, noting the crater is too small for that much dust and the extinction took way longer than a dust cloud would last, so he concludes the asteroid couldn't be the cause.
Conclusion: The extinction of the dinosaurs was caused by something other than an asteroid impact.
Reasoning: The crater in the Yucatán is too small to have produced the required amount of dust, and the extinction process lasted many years, whereas the dust cloud effect would have been relatively brief.
Analysis: Trent identifies a gap in Selena's specific 'dust cloud' theory and uses it to dismiss the 'asteroid' theory entirely. This is a massive leap. For Trent's argument to work, he must assume that there is no other way an asteroid could have caused a long-term extinction. If an asteroid could cause extinction through some other mechanism besides a dust cloud, Trent's conclusion falls apart. Look for an assumption that links the failure of the dust theory to the failure of the asteroid theory as a whole.
Conclusion: The extinction of the dinosaurs was caused by something other than an asteroid impact.
Reasoning: The crater in the Yucatán is too small to have produced the required amount of dust, and the extinction process lasted many years, whereas the dust cloud effect would have been relatively brief.
Analysis: Trent identifies a gap in Selena's specific 'dust cloud' theory and uses it to dismiss the 'asteroid' theory entirely. This is a massive leap. For Trent's argument to work, he must assume that there is no other way an asteroid could have caused a long-term extinction. If an asteroid could cause extinction through some other mechanism besides a dust cloud, Trent's conclusion falls apart. Look for an assumption that links the failure of the dust theory to the failure of the asteroid theory as a whole.
Passage Stimulus
Passage Redacted
Unlock Full Passage17.Trent's argument assumes that
Correct Answer
E
E is necessary for Trent’s reasoning. If more than one large asteroid struck during the extinction period, then the cumulative dust (and staggered effects) could explain both the dust requirement and the multi-year timeline, undermining Trent’s conclusion that the extinction was not due to asteroid impact. Negation test: If more than one large asteroid struck, Trent’s argument falls apart; therefore, E is required.
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