The correct option is
C Keep at a distance
To “hold off” means to delay an action, it also means to keep something away from someone, usually from dangers.
“Restrain” means to prevent from doing something.
“Exhibit” means to show something.
“Keep at a distance” means to keep away from something special
“Continue” means to persist in an activity.
“Offer” means any proposal made that is subject for acceptance or rejection.
Hence option C is the correct answer because it is the correct meaning of the given phrase.