How to hand this situation...

[resboard]

Over the last 3-4 weeks it has been happening more and more and I'm never really sure what to do. Lets say I raise from CO with Ac9c and the bb calls. The flop is Jc 6h 3s. And the button bets 3/4 pot. What is the standard move? of course sometimes he has a piece but most of the time he does not. raising seems to inflate the pot and if he reraises we have to fold. Calling seems to wimpy. What is the best move here?