We 3-bet bluff with J9o but get caught and flop second pair—now what?

Blinds $1-$2, game is $2-$100 spread-limit (max you can raise is $100 over the previous bet). I cover everyone.

HAND: $4 straddle is on. I have Jh9s in BB. UTG ($200)raises to $12 and Button ($200) calls. I don’t believe much in physical tells but trusted this one enough to think UTG was weak and I 3-bet to $45. Straddle folds, UTG indeed folds quickly, but the Buttin ruins my fun by calling. ****!

FLOP: AdJd5c (pot: $100, heads-up).

We:

A) check
B) bet small
C) bet big ?