Final answer:
Layout view allows users to modify a report while seeing the actual data, offering a live preview of changes made to the report's design.
Step-by-step explanation:
The feature that allows you to modify the report while seeing the data is B) Layout view. In Layout view, you can make design changes to the report while it displays data. This allows for a more interactive design experience as you can immediately see how your changes will affect the presentation of the data. Unlike Design view, Layout view does allow for the direct manipulation of the report with live data present which simplifies the design process. Print Preview is used for viewing how the report will look when printed, Report view is for viewing the report without making changes, and Design view is for making structural changes to the report without viewing live data.