Answer: deflate because volume is directly proportional to temperature
Step-by-step explanation:
Charles' Law: This law states that volume is directly proportional to the temperature of the gas at constant pressure and number of moles.
(At constant pressure and number of moles)

where,
= initial volume of gas
= final volume of gas
= initial temperature of gas
= final temperature of gas
As volume is directly proportional to temperature, as the balloon is kept in freezer, the temperature would decrease and thus the volume will decrease and it will deflate.