Which option should be turned off if summary data should not allow interaction?

The choice to turn off "Allow sorting" is correct when the goal is to prevent interaction with summary data. By disabling this option, users cannot rearrange data based on different criteria, which ensures that the summary remains static and prevents any alterations that could lead to misinterpretations or misuse of the information presented.

Locking view is often confused with restricting interaction, as it can prevent changes to the view settings themselves. However, "Allow sorting" specifically addresses user interactions that would modify the arrangement of the data, which would not be ideal for static summaries meant for high-level overviews.

Similarly, "Show gridlines" and "Default view" do not directly affect user interaction with summary data. Gridlines are about visual representation, which doesn't inherently allow or disallow user actions, and the default view pertains to the initial layout rather than ongoing interaction potential. Therefore, focusing on "Allow sorting" effectively achieves the goal of maintaining the integrity of summary data while discouraging any form of interactive engagement.