Passage Summary: Ice cream sales are down and cheese sales are up. Since both have calcium, the author concludes people are swapping their ice cream for cheese to get their nutrients.

Conclusion: People are increasingly choosing to get their calcium from cheddar cheese instead of ice cream.

Reasoning: Ice cream sales have declined over the last decade while cheddar cheese sales have doubled, and both are sources of calcium.

Analysis: The author is guilty of a 'correlation does not equal causation' error, specifically assuming a specific motivation for a change in consumer behavior. Just because two trends happen at the same time doesn't mean one is causing the other, or that they are linked by a desire for calcium. Look for an answer that highlights the failure to consider alternative explanations, such as cheese becoming cheaper or people simply liking cheese more for reasons unrelated to calcium. The author assumes a level of nutritional intentionality in shoppers that the evidence doesn't support.