Final answer:
The View tab on the Ribbon in Microsoft Word contains the commands for viewing the ruler, gridlines, and navigation pane.
Step-by-step explanation:
The commands for viewing the ruler, gridlines, and navigation pane in a Microsoft Word document can be found under the View tab on the Ribbon. When you click the View tab, you will see options to toggle the ruler, gridlines, and open the navigation pane among other view-related functionalities. This is separate from the Review tab, which is used for accepting or rejecting changes in a document, as well as accessing the reviewing pane to navigate between different revisions. The Home, Page Layout, and other tabs contain different sets of commands for various purposes.