[wiggs73]

I voted for D, but it was a mistake, sort of...

I think you have 2 options here, 1 would be to lead out and the other would be to check-fold in this particular instance.

In practice, I'd almost always lead out here for 2 reasons. 1 is it disguises your hand which makes it easier to extract chips from other hands when a 3rd diamond hits. 2 is that it gives you a way to pick the pot up immediately, and will probably work often when all that happens pre-flop is 1 MP player limps and the SB completes. I can see both players folding often enough so that leading would be profitable, even if you never hit your flush when you get called or raised.

The reason I voted D is because after checking, I would just fold for a pot sized bet. I don't care that it's small relative to your stack; pot odds are pot odds and you aren't getting correct odds to call. I know a lot of people will say, well what about implied odds. But if you check-call down to the river and a 3rd diamond hits, do you really think you're getting paid off? I think the CC line makes your hand fairly transparent and so I'm playin pot odds here more than implied odds. I'd be more inclined to call chasing a draw in a cash game anyway, where I can reload to a full stack after I miss.

If you check and MP does something goofy like min-bet, I would probably check-raise for the same reasons I would lead out. An additional reason I like check-raising a small bet more than a large one, is that you achieve the same effect for less chips. If villain calls a meaningful check-raise to his pot sized bet and the turn blanks, you're going to be in an awkward situation where you've put in ~300 chips, are out of position, and have king-high.