Which option allows a user to view a report without having access to the underlying sheets?

The option that allows a user to view a report without having access to the underlying sheets is to add the report to a dashboard using the Report widget. When a report is placed on a dashboard, it can be accessed by users who may not have permission to view the original sheets that the report is based on. This functionality is particularly useful for sharing summarized data and insights with stakeholders who need to view the information without being granted full access to the underlying data sources.

In contrast, sharing the report link typically requires the recipient to have access permissions to the report's source sheets. Exporting the report as a PDF provides a static view of the report at a certain point in time, but it does not offer interactive capabilities and may not serve the same purpose as displaying it on a dashboard. Creating a summary of the report is more about condensing or highlighting key information for easier consumption, but it does not inherently change the access permissions related to the underlying data. Thus, placing the report on a dashboard is the best method to allow users visibility without granting them access to the original sheets.