The correct answer is Ctrl+A
To select the entire document the keyboard shortcut CTRL+A is used.
Additional Information
Word shortcut keys
- Ctrl + A -- Select all contents of the page.
- Ctrl + B -- Bold highlighted selection.
- Ctrl + C -- Copy selected text.
- Ctrl + X -- Cut selected text.
- Ctrl + N -- Open new/blank document.
- Ctrl + O -- Open options.
- Ctrl + P -- Open the print window.
- Ctrl + F -- Open find box.



