Answer :
The correct answer is:
1. The Protect Worksheet function needs to be enabled.
To lock or unlock cells in Excel, you must:
1. Select the cells you want to lock or unlock.
2. Go to the "Review" tab in the ribbon.
3. Click "Protect Sheet" or "Protect Worksheet".
4. Check or uncheck "Select unlocked cells" and "Select locked cells" as needed.
Locking cells:
- Prevents editing, formatting, and deletion.
- Requires password to unlock (optional).
Unlocking cells:
- Allows editing, formatting, and deletion.
Enabling Protect Worksheet:
1. Goes to Review tab.
2. Click Protect Sheet.
3. Choose password (optional).
4. Select permissions.
Without Protect Worksheet enabled:
- Locking/unlocking cells has no effect.
- Cells remain editable.
The other options are incorrect because:
- No functions need to be enabled other than lock/unlock cells: Incorrect. Protect Worksheet must be enabled.
- Worksheet must be saved before cells become locked/unlocked: Incorrect. Saving is not required for locking/unlocking cells.
Best practices:
- Use strong passwords for protected worksheets.
- Document protected worksheets for future reference.
- Use Excel's built-in permissions for collaborative workflows.
