Less than 15 min. after I put up the previous post, I realized that I knew the answer and had known the answer pretty much from the time the question was asked. It just took a bit for me to realize that. I spoke with movie.girl on the ride home afterwards, and, similar to that, the previous post (and possibly this one) was looking for confirmation of my decision.
But no matter that I want confirmation and approval, I don't need it.
The answer is easy, far easier than I let on. I like her too much for (a). I don't want to do (c) if I don't have to. The answer is (b2), as in hang out as friends but less often and with some clear boundaries.
I don't want a non-exclusive relationship with someone I really like. I may not know what I want in life or my career, but I know what I want with relationships. I also feel that it's a little insulting. "I don't want to date you, but you're still good enough for a non-committed relationship." I know that's not the intent, and I don't think I feel it (much), but it is a subtext. And I do enjoy pride - probably not my favorite of the sins, but it's certainly up there.
As for what I expected, I know what I expected. I always did. I wanted to date her until I couldn't. If she was moving away, fine, but until she did I was ready to go out with her, to go with it, and see what happened. I was not, and am not, ready for an open relationship.
Maybe I'm too traditional or conservative or what-not for that sort of thing. I feel that it just doesn't jive with me. And that's the essence of this. Know thyself. And I do, at least at this time, in this respect.
So no, it wasn't a difficult question. The difficulty lay in understanding my answer. Oh I'll be a bit sad over this, but it's also been a positive experience for me. Perhaps more on that another time.