Final answer:
AccessData Registry Viewer allows users to view a report and its content before finalizing it through the Preview mode. This feature helps ensure the accuracy and completeness of the report's keys and values.
Step-by-step explanation:
When using AccessData Registry Viewer, the method that allows you to view the report and its content prior to generating a report to confirm the added keys is Preview mode (a). This feature is essential for verifying the accuracy of the information that will be included in the report. Preview mode serves as a way to double-check the selected keys and values that are intended to be part of the final document, ensuring that no critical data is missing or incorrectly included before the full report generation.