Which window provides the default output format for SAS 9.3?

The Output + Results Viewer window is indeed the correct answer because it serves as the primary interface for displaying the results of SAS operations in SAS 9.3. This window not only presents the output from procedures but also allows users to view and interact with the results, such as tables and graphs generated from their SAS code.

By default, when you run a SAS program, the Output + Results Viewer captures the output produced by the SAS procedures, formatting it in a user-friendly manner for easy analysis and interpretation. This makes it an essential part of the SAS programming experience, as it directly relates to how users can view and interact with their data analysis results.

Other windows, such as the Log window, focus on providing messages about the execution of SAS programs, including warnings and errors, rather than output formatting. The Editor window is primarily used for writing and editing SAS code, while the Explorer window is designed for navigating and managing SAS libraries, datasets, and other resources. Thus, these other options do not serve the same purpose as the Output + Results Viewer.