An argument recommends increasing advertising spending based on a recent, brief surge in product sales. What specific additional information would be most crucial for the *author* of the argument to consider to make their recommendation more robust?

✓ Correct Answer: Option B

To make a robust recommendation, the author needs to establish a clear cause-and-effect relationship. Historical data on advertising and sales can help determine if the recent surge was an anomaly or part of a trend directly tied to spending.