Passage Summary: Low-fat vanilla ice cream tastes bad, but low-fat chocolate tastes great, probably because chocolate's many ingredients hide the missing fat.

Conclusion: The chemical complexity of chocolate is likely what hides the taste difference caused by removing fat.

Reasoning: Vanilla is chemically simple and its low-fat version tastes bad, whereas chocolate is complex and its low-fat version tastes fine.

Analysis: To strengthen this causal argument, we need to bolster the link between flavor complexity and the masking of fat. Look for an answer that provides more evidence that complexity—and not some other factor like sugar content or texture—is the reason for the taste success. We want to see that when complexity is high, fat removal is less noticeable, or perhaps that when complexity is low in other flavors, fat removal is always noticeable.