When you delete a groupbox the controls inside it are . . . . . . . .

The correct answer is: D. Deleted

When you delete a groupbox, all of the controls inside it are deleted as well. This is because groupboxes are containers for controls, and when the container is deleted, the contents are deleted as well.

Option A is incorrect because the controls are not retained when the groupbox is deleted.

Option B is incorrect because the controls are not given to another groupbox when the groupbox is deleted.

Option C is incorrect because data loss does not occur when you delete a groupbox. The controls inside the groupbox are deleted, but the data that they contain is not lost.

I hope this helps! Let me know if you have any other questions.