A fined tuned argument.....Heywood style.

[Esquilax]

The fine tuning problem is this: There are about couple of dozen physical constants of the universe teetering on a knife edge....which if you changed anyone just a little bit we would not have an emergent universe(or at the very least a much less emergent universe). For instance if gravity were a little stronger the universe would exist as simple black hole. If gravity were a little weaker matter would not clump to form more complex structures.

Now demonstrate that the universe was designed to be as it is now; if you can't demonstrate a designer in the first place than the idea that it arose even out of random chance isn't a problem for anyone. It's like demanding that there must be a designer for a rockslide because the chances of all those rocks just landing in those exact spatial positions is very low; you're technically correct about the odds, but you've not shown why the rocks being in those particular positions is the "success" state for them.

Right now, all you're doing is asserting that, of all the possible universes we could have had, this one was the preferred state; the only sense in which low probabilities could ever be a problem is if you're looking at it like a "million to one" chance where something is hoping for a specific outcome against the odds. That's the only scenario in which the low probability outcome is at all remarkable. I mean, all the other potential universes have the same probability of happening, if you're willing to go specific enough.

The observance of this fact of reality cries out for an explanation. There really are just 4 possible explanations that I can see.

And way to beg the question by adding the term "fine tuning" to three of the four possible answers, even the natural possibility, which would in no way be considered fine tuned.

The extreme fine tuning of the cosmological constant allows me to dismiss D. If it was different by one part in a trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion complex structures would not be able to form. It is unreasonable to think we hit a jackpot with those kind of odds. As Leonard Susskind put it, "Its too much of a stretch".

Sorry, but I'm not going to accept this equivocation between the improbable and the impossible; the chances of something happening being low is not the same as being zero. As I pointed out earlier, the chances of all other potential universes eventuating is exactly the same as this one, given the level of detail you're willing to go to. Improbable things happen all the time, and the only way you could characterize this one as particularly impressive is by indulging in anthropocentric thinking, as though this were somehow the preferred state that something was hoping to get.

Incidentally, it's interesting that you brought up Susskind here, because last I checked he was an atheist; evidently, whatever he sees in the universe isn't the same thing as what you see.

I dimiss C on the grounds as there is no reason to believe this since many coherent models of the universe can be made given our current understanding of physics. Further cutting edge physics...like string theory continue to suggest the possibility the universe could have been different.

Argument from ignorance: I can't conceive of it and neither can current science, therefore it's definitely not true.

That leaves me with A and B as being the only credible explanations. If I assume the principle of indifference applies here, that means I should give A 50% likelihood of being true and B 50% likelihood of being true.

No, because you've got to modulate those possibilities in accordance with the evidence. The only way they'd have exactly equal chances of being true is in an information vacuum.