What does cloud computing

Don't look a gift horse in the mouth

Devil's Advocate

Hear it on the grapevine

The difficulty is trying to spot something big before it becomes a problem but not crying bee too often.

To pick holes

Have sticky fingers

In the following question a proverb/idiom us given. Select the option that best describes the meaning of the given proverb/idiom.

Can't cut the mustard

Fill in the blank given below using the correct idiom. 

Select the idiom/phrase that most accurately and contextually replaces the bolded segment.