Which action should you take first to inspect a document in Excel?

To effectively inspect a document in Excel, the best initial action is to click on "Check for Issues." This option is integral to the process of reviewing and identifying potential problems within the Excel file, such as audit errors, compatibility issues, and hidden elements that are not visible in the standard view.

The "Check for Issues" tool specifically enables users to access features such as "Inspect Document," which scans the document for various types of elements, including comments, tracked changes, hidden rows, and any personal information that might be embedded in the file. This thorough inspection allows users to ensure the document is polished and complies with required standards before sharing or submitting it.

While accessing the Review tab can offer some related tools for assessing comments and changes, and the Developer tab provides options for advanced functions and code, these are not the primary tools for conducting an overall inspection of the document's integrity. Saving the document, although a necessary step at various points in the editing process, does not serve any inspection purpose. Thus, beginning with "Check for Issues" is logically the most effective approach to ensuring a thorough review of the document in Excel.