Which of the following cannot be done with document version?

A saved 'version' of a document is a read-only snapshot of its content captured at a specific point in time (for example, MS Word/Office 365 Version History, or the revision history in SharePoint and Google Docs). Version-management tools let a user open, restore, delete, or print an existing version, but they do not let the content of that saved snapshot itself be edited — any edit is made to the current/live copy, which then becomes a new version.

Checking each listed action against a saved version:

• Modifying a version — not possible: a stored version is locked as a historical record; to change its wording it must first be restored to become the current document and edited there, leaving the original snapshot unchanged.

• Deleting a version — possible: an old or unwanted version can be removed to free up storage once it is no longer needed.

• Opening a version — possible: any saved version can be opened to view its exact content at that point in time.

• Printing a version — possible: once a version is opened, it can be sent to a printer like any other document.

This is why version-history features in common tools (Word, SharePoint, Google Docs) always route an edit through a 'Restore' step first — restoring turns a past version into the live document, which can then be edited and is saved as a new version, rather than letting the old snapshot change in place. So among the listed actions, only modifying a version directly is not possible; the other three are standard supported operations, so 'none of these' does not apply either. This is different from editing the document currently open — that is always possible; what is not possible is editing an already-saved past version without first restoring it.