A6o in SB multiway

[RobA]

One hand I know I screwed up from my last session. It was a spot i've screwed up before, I just want to hear some comments.

10-20 live in AC. 10 handed. Somewhat loose game, maybe 4-5 to flop on average.

I have A6o in SB. 4 limpers. (Main villain is CO - the last limper. He has about 4 full racks of chips in front of him. He's a little loose pre-flop, but is getting paid big-time post-flop. I have trouble believing him, maybe so do others, and maybe thats why he has 4 racks.) I complete. BB checks.

Flop is K76 rainbow. Check to CO, who bets.

Does anybody fold pre-flop? What's my best play here on the flop, and for the rest of the hand given certain outcomes?

Thank you for your comments.