I guess I should answer my own question.
I voted for the middle option.
At this point, all I've done is to start buying "free range" chicken so that the chickens are at least allowed to have a fairly normal chicken life instead of being packed into those awful chicken warehouses with their beaks cut off. Plus I figure it must be healthier to eat chickens that weren't shot up with steroids. And I've never touched veal because of how the calves are treated. But basically that's the only change I've made since becoming a Buddhist -- try to be conscious to support meat industries that don't mistreat the animals while they're alive and to reduce my meat consumption somewhat.
I don't know if that is enough. But then again there is the argument that in any grain or vegetable harvest many millions of sentient beings like insects, earthworms, field mice, and so on are killed.
So, perhaps it's better to have one cow killed and eat from it for a month?
I really don't know...