• Running the report multiple times and look for a variance in the results
• Using the Append aggregation threshold columns option in *the Query editor*
• Checking the aggregation thresholds for the event tables in the Schema explorer

The correct answer is: Using the Append aggregation threshold columns option in *the Query editor*

Explanation: Amazon Marketing Cloud’s Query Editor allows users to append aggregation threshold columns to their query results. By enabling this option, additional columns are included in the output to show whether NULL values are resulting from AMC’s privacy-based aggregation thresholds rather than being naturally present in the data. This gives you visibility into privacy-driven suppression of granular data, distinguishing true NULLs from those forced by system limitations.

Official Reference URL: https://advertising.amazon.com/API/docs/en-us/guides/amazon-marketing-cloud/amc-sql/overview