What would you expect to happen to a balloon filled with air if it was put into a refrigerator

We know that,

when we heat air it expands
when we freeze air it decreases (shrink)

This is because when air is heated the molecules move faster and it tries to go to more places.
But, when the air is in cold place or if it is fridgedthe air molecules become sloweras the molecules become slower..it tends to cover less space as it is not moving fastSo, the volume of air shrinks if it is in cold place.

 So, the answer to your question isthe balloon filled with air shrinks in volume  if it was put into a refrigerator.