Folding is not the right option cuz u probably have the best hand. All in is too agressive, cuz u might be beat with K9 K10 QJ or 910. A normal reraise will tell u where u stand in the hand. one of 3 actions will tell u what to do.

1. if he reraises or goes all in, u can fold cuz more often than not ur beat
2. if he folds then u know u had the best of it
3. if he calls then he probably had top pair and/or some draw and u can act accordingly on the turn