How do I make a pop-up appear after a collision box is hit?

I am making a trivia game and I want the last answer of each section to pop up a window upon hitting a collision box, allowing the user to either advance or go back to the main menu. If you can please help, I would greatly appreciate thanks from a newbie Unity user!

You can use Mathf.Lerp to move your pop up window to the screen…
You have to do this in OnCollisionEnter()

Or you can use iTween Class, It has many effects for these kind of things… See iTween @ iTween

I want the pop-up window to be a sort of GUI on screen item with buttons either advancing the player or returning them back to the main screen. Will this be able to be accomplished with the above method?