Multiple choice general knowledge Don't worry about the stereo. It's still _____ so we can get it fixed. with guarantee to guarantee over guarantee under guarantee Reveal answer Fill a bubble to check yourself D Correct answer Explanation The correct answer is 'under guarantee' because this is the correct English idiom. When something is covered by a warranty, we say it is 'under guarantee' or 'under warranty'. 'With', 'to', and 'over' are not used with 'guarantee' in this context.