Given how limitless the combinations of seating arrangements can be, I'm sure there are studies out there. There are certainly a number of theories proposed regarding the seating of knowledge workers, and my opinion is you have to pick and choose from your favorite theories based on the nature of the team, the nature of the work, and other factors in the environment.
Here's some of the theories I've seen most:
Open seating - proposed largely by agile software development practices, and high-interaction models of work - fits most closely with your Option A. The main idea being that you seat people in a way that will optimize for communication - staring at each other helps you figure out more easily that the other folks in the room need to (or are) communicating and in an environment where the team is the key ingredient, this is the favorite choice.
Context switch minimization - you'll see it a lot in the writings of Joel Spoelsky, and many others - the proposed perfection is something like offices for everyone, with doors that close and distration minimization efforts. The idea being that once an engineer hits a state of "flow", where he's uploaded all the key ingredients to solving the problem/creating the new thing - that he needs a minimum of distraction to keep that state of mind intact for as long as possible. That fits with your option B to a certain extent, particularly in a case where you can't have offices.
My reality-check based on a few too many management books
1 - Mixing and matching rarely works
You can't have a high interation/low context switch scenario. While they aren't mutually exclusive, necessarily, there is no perfect seating arrangement that does both perfectly. Once you arrange people so they are tuned in (option A), you will end up increasing context switches - some are good (hey, you're struggling... what's wrong? can I help?)... some are inane (what the heck was that face? Oh... my coffee is cold, I'm going to go heat it up... hey - great game on TV last night, huh?).
My first gut reaction as a middle manager is if that if you gave me option C, I'd say "what's the point?" - are you mixing and matching for the sake of it? I'd only propose this if there was some particular reason why two people (at the top of th picture) have a particular reason to stare at each other more than the other two. For some completely physical reason (the walls on that part of the room have no power outlets...)
2 - Space trumps all
Due to the cost and complexity of office rooms, you'll rarely see a corporate environment that doesn't include a factor of this. Where the power outlets are, where the heating/cooling blows, and how many people we have to pack in this space will trump idealistic team communication stuff every time. So, when you walk into a room and think "what on earth where they thinking?", figure that there's probably a physical aspect of the environment worth asking about.
3 - Equality and Rank are important
All of your systems seem to assume a reasonably similar rank of person. For example, there is no manager office, or need for any other specialized job function.
More subtle are things like access to windows... sometimes people love it, and crave it, other times, they avoid it. It's important to be aware of the tone set with stuff like premiere space - people can get really jumpy about it.
4 - No matter what you do, someone will find a way to hate it.
The corallary being - "do what you can and then let it go" - someone always wants something else. There's never a perfect case. If you set "everyone is happy" as your goal, you are bound to fail. My preferred goal is "most people can live with it, a few are happy about it, and it doesn't impede getting work done".
Also - with any new environment, there's a 1-2 month bake in time where people will be unhappy simply because change = bad.
5 - Corporate culture is an influencer
That doesn't mean that you need to avoid bucking the system. But realize that it's a factor. For example:
same old, same old - for this company will get less complaining, and an assumption of "that's how it is" conveyed to new people.
new and different - will usually wake people up to the fact that the world has change and something new is in the mix. This is a great thing for cases where you want a new process and for people to realize that it's more than just a fresh coat of paint over business as usual.
Putting the right people together matters more than the configuration
By this I mean - if your configuration is such that people are annoying the heck out of each other, or good people are getting left out unintentionally - then you have a bigger problem than anything a perfect theory will help you fix.
Where your managers go, where your great partners at doing awesome things, where your problem children go... it all factors in. It's amazing what can impact people.