Answer:
To add a password to a SmartArt graphic in Microsoft PowerPoint, follow these steps:
Open the PowerPoint presentation containing the SmartArt graphic that you want to add a password to.
Select the SmartArt graphic by clicking on it.
In the ribbon at the top of the window, click the "Format" tab.
In the "Format" tab, click the "Security" button.
In the "Security" dialog box that appears, click the "Password" tab.
In the "Password" tab, enter a password in the "Password" field.
Re-enter the password in the "Confirm password" field to confirm it.
Click the "OK" button to save the password.
Save the presentation. The SmartArt graphic will now be protected with the password that you set. You will need to enter the password to edit or modify the SmartArt graphic.