Passage Summary: Yuriko claims a new ad campaign caused a 30 percent rise in vaccinations. Susan counters by pointing out that most of that rise happened right when free clinics opened, before the ads even started.

Conclusion: Yuriko's evidence does not necessarily prove that the vaccination campaign was the cause of the increase in vaccinations.

Reasoning: The majority of the vaccination increase happened before the campaign was fully active and coincided with the opening of free health clinics.

Analysis: Susan is employing a classic 'alternative cause' strategy to undermine Yuriko's causal claim. She doesn't deny that vaccinations went up; instead, she introduces a chronological fact that suggests a different event—the opening of free clinics—is the more likely culprit. When looking for the correct description of her method, focus on how she uses the timing of events to suggest that the 'effect' (increased vaccinations) began before the 'cause' (the campaign) was actually in place. She is essentially providing a more plausible explanation for the data Yuriko provided.